RFC 8913: Two-Way Active Measurement Protocol (TWAMP) YANG Data Model
- R. Civil,
- A. Morton,
- R. Rahman,
- M. Jethanandani,
- K. Pentikousis, Ed.
Abstract
This document specifies a data model for client and server implementations of the Two-Way Active Measurement Protocol (TWAMP). This document defines the TWAMP data model through Unified Modeling Language (UML) class diagrams and formally specifies it using the YANG data modeling language (RFC 7950). The data model is compliant with the Network Management Datastore Architecture (NMDA).¶
Status of This Memo
This is an Internet Standards Track document.¶
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.¶
Information about the current status of this document, any
errata, and how to provide feedback on it may be obtained at
https://
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://
1. Introduction
The Two-Way Active Measurement Protocol (TWAMP) [RFC5357] is used to measure network performance parameters such as latency, bandwidth, and packet loss by sending probe packets and measuring their experience in the network. To date, TWAMP implementations do not come with a standard management framework, and, as such, implementers have no choice except to provide a proprietary mechanism. This document addresses this gap by defining the model using Unified Modeling Language (UML) class diagrams [UML] and formally specifying a TWAMP data model that is compliant with the Network Management Datastore Architecture (NMDA) [RFC8342], using YANG 1.1 [RFC7950].¶
1.1. Motivation
In current TWAMP deployments, the lack of a standardized data model
limits the flexibility to dynamically instantiate TWAMP-based
measurements across equipment from different vendors. In large,
virtualized, and dynamically instantiated infrastructures where
network functions are placed according to orchestration algorithms,
proprietary mechanisms for managing TWAMP measurements pose severe
limitations with respect to programmability
Two major trends call for standardizing TWAMP management aspects.
First, it is expected that in the coming years large-scale and
multi-vendor TWAMP deployments will become the norm. From an
operations perspective, using several vendor-specific TWAMP
configuration mechanisms when one standard mechanism could provide an
alternative is expensive and inefficient. Second, the increasingly
software
1.2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
1.3. Document Organization
The rest of this document is organized as follows. Section 2 presents the scope and applicability of this document. Section 3 provides a high-level overview of the TWAMP data model. Section 4 details the configuration parameters of the data model, and Section 5 specifies in YANG the TWAMP data model. Section 6 lists illustrative examples that conform to the YANG data model specified in this document. Appendix A elaborates these examples further.¶
2. Scope, Model, and Applicability
The purpose of this document is the specification of a
vendor
Figure 1 illustrates a redrawn version of the TWAMP
logical model found in Section 1.2 of TWAMP [RFC5357]. The figure is annotated with pointers to the
UML diagrams [UML] provided in this document and
associated with the data model of the four logical entities in a TWAMP
deployment, namely the TWAMP Control-Client, Server, Session-Sender, and
Session
As per TWAMP [RFC5357], unlabeled links in Figure 1 are left unspecified and may be proprietary protocols.¶
(Figure 3) (Figure 4)
+----------------+ +--------+
| Control-Client | <-- TWAMP-Control --> | Server |
+----------------+ +--------+
^ ^
| |
V V
+----------------+ +-------------------+
| Session-Sender | <-- TWAMP-Test --> | Session-Reflector |
+----------------+ +-------------------+
(Figure 5) (Figure 6)As per TWAMP [RFC5357], a TWAMP implementation
may follow a simplified logical model, in which the same node acts as both
Control-Client and Session-Sender, while another node acts at the
same time as both TWAMP Server and Session
o-------------------o o-------------------o
| Config client | | Config client |
o-------------------o o-------------------o
|| ||
NETCONF || RESTCONF NETCONF || RESTCONF
|| ||
o-------------------o o-------------------o
| Config server | | Config server |
| (Figures 3 and 5) | | (Figures 4 and 6) |
+-------------------+ +-------------------+
| Control-Client | <-- TWAMP-Control --> | Server |
| | | |
| Session-Sender | <-- TWAMP-Test --> | Session-Reflector |
+-------------------+ +-------------------+The data model defined in this document is orthogonal to the specific protocol used between the Config client and Config server to communicate the TWAMP configuration parameters.¶
Operational actions such as how TWAMP-Test sessions are started and stopped, how performance measurement results are retrieved, or how stored results are cleared, and so on, are not addressed by the configuration model defined in this document. As noted above, such operational actions are not part of the TWAMP specification [RFC5357] and hence are out of scope for this document. See also Appendix B. In addition, for operational state, the information provided in the Performance Metrics Registry [RFC8911] and [PERF-METRICS] can be used to develop an independent model for the Performance Metrics that need to be captured and retrieved.¶
3. Data Model Overview
The TWAMP data model includes four categories of configuration items.¶
First, global configuration items relate to parameters that are set on a per-device level. For example, the administrative status of the device with respect to whether it allows TWAMP sessions and, if so, in what capacity (e.g., Control-Client, Server, or both) is a typical instance of a global configuration item.¶
A second category includes attributes that can be configured on a
per‑TWAMP
A third category includes attributes related to
per
Finally, the data model includes attributes that relate to the operational state of the TWAMP implementation.¶
As the TWAMP data model is described in the remaining sections of this document, readers should keep in mind the functional entity grouping illustrated in Figure 1.¶
3.1. Control-Client
A TWAMP Control-Client has an administrative status field set at the device level that indicates whether the node is enabled to function as such.¶
Each TWAMP Control-Client is associated with zero or more TWAMP‑Control connections. The main configuration parameters of each control connection are:¶
- A name that can be used to uniquely identify at the Control-Client a particular control connection. This name is necessary for programmability reasons because at the time of creation of a TWAMP-Control connection not all IP and TCP port number information needed to uniquely identify the connection is available.¶
- The IP address of the interface the Control-Client will use for connections.¶
- The IP address of the remote TWAMP Server.¶
- Authentication and encryption attributes such as KeyID, Token, and the Control-Client Initialization Vector (Client-IV); see also Section 3.1 of "A One-way Active Measurement Protocol (OWAMP)" [RFC4656] and "Randomness Requirements for Security" [RFC4086].¶
Each TWAMP-Control connection, in turn, is associated with zero or more TWAMP-Test sessions. For each test session, the following configuration items should be noted:¶
- The test session name, which uniquely identifies a particular test session at the Control-Client and Session-Sender. Similar to the control connections mentioned above, this unique test session name is needed because at the time of creation of a TWAMP-Test session, for example, the source UDP port number is not known to uniquely identify the test session.¶
- The IP address and UDP port number of the Session-Sender on the path under test by TWAMP.¶
- The IP address and UDP port number of the Session
-Reflector on said path.¶ - Information pertaining to the test packet stream, such as the test starting time; which Performance Metric is to be used, as defined in "Registry for Performance Metrics" [RFC8911]; or whether the test should be repeated.¶
3.2. Server
Each TWAMP Server has an administrative status field set at the device level to indicate whether the node is enabled to function as a TWAMP Server.¶
Each Server is associated with zero or more TWAMP-Control connections. Each control connection is uniquely identified by the 4-tuple {Control-Client IP address, Control-Client TCP port number, Server IP address, Server TCP port}. Control connection configuration items on a TWAMP Server are read-only.¶
3.3. Session-Sender
A TWAMP Session-Sender has an administrative status field set at the device level that indicates whether the node is enabled to function as such.¶
There is one Session-Sender instance for each TWAMP-Test session that is initiated from the sending device. Primary configuration fields include:¶
- The test session name, which MUST be identical to the corresponding test session name on the TWAMP Control-Client (Section 3.1).¶
- The control connection name, which, along with the test session name, uniquely identifies the TWAMP Session-Sender instance.¶
- Information pertaining to the test packet stream, such as the number of test packets and the packet distribution to be employed; see also "Network performance measurement with periodic streams" [RFC3432].¶
3.4. Session-Reflector
Each TWAMP Session
Each Session
Read-only access to other data model parameters, such as the Sender IP address, is foreseen. Each test session can be uniquely identified by the 4-tuple mentioned in Section 3.2.¶
4. Data Model Parameters
This section defines the TWAMP data model using UML [UML] and introduces selected parameters associated with the four TWAMP logical entities. The complete TWAMP data model specification is provided in the YANG module presented in Section 5.2.¶
4.1. Control-Client
The client container (see Figure 3) holds items that are related to the configuration of the TWAMP Control-Client logical entity (recall Figure 1).¶
The client container includes an administrative configuration
parameter
+-------------+
| client |
+-------------+ 1..* +-----------------------+
| admin-state |<>----------------------| mode-preference-chain |
| | +-----------------------+
| | 1..* +------------+ | priority |
| |<>-----| key-chain | | mode |
+-------------+ +------------+ +-----------------------+
^ | key-id |
V | secret-key |
| +------------+
| 0..*
+------------------------+
| ctrl-connection |
+------------------------+
| name |
| client-ip |
| server-ip |
| server-tcp-port | 0..* +----------------------+
| control-packet-dscp |<>-------| test-session-request |
| key-id | +----------------------+
| max-count | | name |
| client-tcp-port {ro} | | sender-ip |
| server-start-time {ro} | | sender-udp-port |
| state {ro} | | reflector-ip |
| selected-mode {ro} | | reflector-udp-port |
| token {ro} | | timeout |
| client-iv {ro} | | padding-length |
+------------------------+ | test-packet-dscp |
| start-time |
+-------------+ 1 | repeat |
| pm-reg-list |------<>| repeat-interval |
+-------------+ | state {ro} |
| pm-index | | sid {ro} |
+-------------+ +----------------------+The client container holds a list
Depending on the modes available in the Server Greeting, the
Control-Client MUST choose the highest
Note that the list of preferred modes may set multiple bit positions independently, such as when referring to the extended TWAMP features in "Mixed Security Mode for the Two-Way Active Measurement Protocol (TWAMP)" [RFC5618], "Individual Session Control Feature for the Two-Way Active Measurement Protocol (TWAMP)" [RFC5938], "Two-Way Active Measurement Protocol (TWAMP) Reflect Octets and Symmetrical Size Features" [RFC6038], and "IKEv2-Derived Shared Secret Key for the One-Way Active Measurement Protocol (OWAMP) and Two-Way Active Measurement Protocol (TWAMP)" [RFC7717]. If the Control-Client cannot determine an acceptable mode, or when the bit combinations do not make sense, e.g., authenticated and unauthenticated bits are both set, it MUST respond with zero Mode bits set in the Set-Up-Response message, indicating that it will not continue with the control connection.¶
In addition, the client container holds a list named "key-chain", which relates key-id with the respective secret-key. Both the Server and the Control-Client use the same mappings from key-id to secret‑key (in Figure 3); in order for this to work properly, key-id must be unique across all systems in the administrative domain. The Server, being prepared to conduct sessions with more than one Control-Client, uses key-id to choose the appropriate secret-key; a Control-Client would typically have different secret keys for different Servers. The secret-key is the shared secret, of type "binary", and the length SHOULD contain at least 128 bits of entropy. The key-id and secret-key encoding SHOULD follow Section 9.8 of YANG [RFC7950]. The derived key length (dkLen as defined in "PKCS #5: Password-Based Cryptography Specification Version 2.1" [RFC8018]) MUST be 16 octets for the AES Session-key used for encryption and 32 octets for the HMAC-SHA1 Session-key used for authentication; see also Section 6.10 of OWAMP [RFC4656].¶
Each client container also holds a list of control connections, where each item in the list describes a TWAMP-Control connection initiated by this Control-Client. There SHALL be one ctrl-connection per TWAMP-Control (TCP) connection that is to be initiated from this device.¶
In turn, each ctrl-connection holds a test
There SHALL be one instance of test
The Control-Client is also responsible for scheduling TWAMP-Test
sessions; therefore, test
4.2. Server
The server container (see Figure 4) holds items that are related to the configuration of the TWAMP Server logical entity (recall Figure 1).¶
The server container includes an administrative configuration
parameter
A device operating in the Server Role cannot configure attributes
on a per
+---------------------+
| server |
+---------------------+
| admin-state | 1..* +------------+
| server-tcp-port |<>------| key-chain |
| servwait | +------------+
| control-packet-dscp | | key-id |
| count | | secret-key |
| max-count | +------------+
| modes |
| | 0..* +--------------------------+
| |<>------| ctrl-connection |
+---------------------+ +--------------------------+
| client-ip {ro} |
| client-tcp-port {ro} |
| server-ip {ro} |
| server-tcp-port {ro} |
| state {ro} |
| control-packet-dscp {ro} |
| selected-mode {ro} |
| key-id {ro} |
| count {ro} |
| max-count {ro} |
| salt {ro} |
| server-iv {ro} |
| challenge {ro} |
+--------------------------+Each server container holds a list named "key-chain", which relates key-id with the respective secret-key. As mentioned in Section 4.1, both the Server and the Control-Client use the same mapping from key‑id to the shared secret-key; in order for this to work properly, key-id must be unique across all the systems in the administrative domain. The Server, being prepared to conduct sessions with more than one Control-Client, uses key-id to choose the appropriate secret-key; a Control-Client would typically have different secret keys for different Servers. key-id tells the Server which shared secret-key the Control-Client wishes to use for authentication or encryption.¶
Each incoming control connection active on the Server is
represented by a ctrl
4.3. Session-Sender
The session-sender container, illustrated in Figure 5, holds items that are related to the configuration of the TWAMP Session-Sender logical entity.¶
The session-sender container includes an administrative parameter
+----------------+
| session-sender |
+----------------+ 0..* +---------------------------+
| admin-state |<>-----| test-session |
+----------------+ +---------------------------+
| name |
| ctrl-connection-name {ro} |
| fill-mode |
| number-of-packets |
| state {ro} |
| sent-packets {ro} |
| rcv-packets {ro} |
| last-sent-seq {ro} |
| last-rcv-seq {ro} |
+---------------------------+
^
V
| 1
+---------------------+
| packet-distribution |
+---------------------+
| periodic / poisson |
+---------------------+
| |
+-------------------+ |
| periodic-interval | |
+-------------------+ |
|
+--------------+
| lambda |
| max-interval |
+--------------+Each TWAMP-Test session initiated by the Session-Sender will be represented by an instance of a test-session object. There SHALL be one instance of test-session for each TWAMP-Test session for which packets are being sent.¶
4.4. Session-Reflector
The session
The session
A device operating in the Session
+-------------------+
| session-reflector |
+-------------------+
| admin-state |
| refwait |
+-------------------+
^
V
|
| 0..*
+----------------------------------------+
| test-session |
+----------------------------------------+
| sid {ro} |
| sender-ip {ro} |
| sender-udp-port {ro} |
| reflector-ip {ro} |
| reflector-udp-port {ro} |
| parent-connection-client-ip {ro} |
| parent-connection-client-tcp-port {ro} |
| parent-connection-server-ip {ro} |
| parent-connection-server-tcp-port {ro} |
| test-packet-dscp {ro} |
| sent-packets {ro} |
| rcv-packets {ro} |
| last-sent-seq {ro} |
| last-rcv-seq {ro} |
+----------------------------------------+Each incoming TWAMP-Test session that is active on the
Session
Instances of test-session are indexed by a Session Identifier (SID) (the sid parameter). This SID value is auto-allocated by the TWAMP Server as test session requests are received and is communicated back to the Control-Client in the SID field of the Accept-Session message; see Section 4.3 of "Two-Way Active Measurement Protocol (TWAMP) Reflect Octets and Symmetrical Size Features" [RFC6038].¶
When attempting to retrieve operational data for active test
sessions from a Session
If the user has no network access to the Control-Client device,
then the only option is to retrieve all test-session instances from
the Session
Each Session
5. Data Model
This section formally specifies the TWAMP data model using YANG.¶
5.1. YANG Tree Diagram
This section presents a simplified graphical representation of the TWAMP data model using a YANG tree diagram. Readers should keep in mind that the limit of 72 characters per line forces us to introduce artificial line breaks in some tree diagram nodes. Tree diagrams used in this document follow the notation defined in "YANG Tree Diagrams" [RFC8340].¶
Please note that the backslash ('\') character near the end of the
diagram is used for formatting purposes only
(i.e., "reflector‑udp‑
module: ietf-twamp
+--rw twamp
+--rw client {control-client}?
| +--rw admin-state? boolean
| +--rw mode-preference-chain* [priority]
| | +--rw priority uint16
| | +--rw mode? twamp-modes
| +--rw key-chain* [key-id]
| | +--rw key-id string
| | +--rw secret-key? binary
| +--rw ctrl-connection* [name]
| +--rw name string
| +--rw client-ip? inet:ip-address
| +--rw server-ip inet:ip-address
| +--rw server-tcp-port? inet:port-number
| +--rw control-packet-dscp? inet:dscp
| +--rw key-id? string
| +--rw max-count-exponent? uint8
| +--ro client-tcp-port? inet:port-number
| +--ro server-start-time? uint64
| +--ro repeat-count? uint64
| +--ro state?
| | control-client-connection-state
| +--ro selected-mode? twamp-modes
| +--ro token? binary
| +--ro client-iv? binary
| +--rw test-session-request* [name]
| +--rw name string
| +--rw sender-ip? inet:ip-address
| +--rw sender-udp-port? union
| +--rw reflector-ip inet:ip-address
| +--rw reflector-udp-port? inet:port-number
| +--rw timeout? uint64
| +--rw padding-length? uint32
| +--rw test-packet-dscp? inet:dscp
| +--rw start-time? uint64
| +--rw repeat? uint32
| +--rw repeat-interval? uint32
| +--rw pm-reg-list* [pm-index]
| | +--rw pm-index uint16
| +--ro state? test-session-state
| +--ro sid? string
+--rw server {server}?
| +--rw admin-state? boolean
| +--rw server-tcp-port? inet:port-number
| +--rw servwait? uint32
| +--rw control-packet-dscp? inet:dscp
| +--rw count? uint8
| +--rw max-count-exponent? uint8
| +--rw modes? twamp-modes
| +--rw key-chain* [key-id]
| | +--rw key-id string
| | +--rw secret-key? binary
| +--ro ctrl-connection*
| [client-ip client-tcp-port server-ip server-tcp-port]
| +--ro client-ip inet:ip-address
| +--ro client-tcp-port inet:port-number
| +--ro server-ip inet:ip-address
| +--ro server-tcp-port inet:port-number
| +--ro state? server-ctrl-connection-state
| +--ro control-packet-dscp? inet:dscp
| +--ro selected-mode? twamp-modes
| +--ro key-id? string
| +--ro count? uint8
| +--ro max-count-exponent? uint8
| +--ro salt? binary
| +--ro server-iv? binary
| +--ro challenge? binary
+--rw session-sender {session-sender}?
| +--rw admin-state? boolean
| +--rw test-session* [name]
| +--rw name string
| +--ro ctrl-connection-name? string
| +--rw fill-mode? padding-fill-mode
| +--rw number-of-packets uint32
| +--rw (packet-distribution)?
| | +--:(periodic)
| | | +--rw periodic-interval decimal64
| | +--:(poisson)
| | +--rw lambda decimal64
| | +--rw max-interval? decimal64
| +--ro state? sender-session-state
| +--ro sent-packets? uint32
| +--ro rcv-packets? uint32
| +--ro last-sent-seq? uint32
| +--ro last-rcv-seq? uint32
+--rw session-reflector {session-reflector}?
+--rw admin-state? boolean
+--rw refwait? uint32
+--ro test-session*
[sender-ip sender-udp-port reflector-ip \
reflector-udp-port]
+--ro sid? string
+--ro sender-ip inet:ip-address
+--ro sender-udp-port
| dynamic-port-number
+--ro reflector-ip inet:ip-address
+--ro reflector-udp-port inet:port-number
+--ro parent-connection-client-ip? inet:ip-address
+--ro parent-connection-client-tcp-port? inet:port-number
+--ro parent-connection-server-ip? inet:ip-address
+--ro parent-connection-server-tcp-port? inet:port-number
+--ro test-packet-dscp? inet:dscp
+--ro sent-packets? uint32
+--ro rcv-packets? uint32
+--ro last-sent-seq? uint32
+--ro last-rcv-seq? uint325.2. YANG Module
This section presents the YANG module for the TWAMP data model defined in this document. The module imports definitions from "Common YANG Data Types" [RFC6991] and references "Framework for IP Performance Metrics" [RFC2330], "Network performance measurement with periodic streams" [RFC3432], "A One-way Active Measurement Protocol (OWAMP)" [RFC4656], "A Two-Way Active Measurement Protocol (TWAMP)" [RFC5357], "Mixed Security Mode for the Two-Way Active Measurement Protocol (TWAMP)" [RFC5618], "Network Time Protocol Version 4: Protocol and Algorithms Specification" [RFC5905], "Individual Session Control Feature for the Two-Way Active Measurement Protocol (TWAMP)" [RFC5938], "Two-Way Active Measurement Protocol (TWAMP) Reflect Octets and Symmetrical Size Features" [RFC6038], "Advanced Stream and Sampling Framework for IP Performance Metrics (IPPM)" [RFC7312], "IKEv2-Derived Shared Secret Key for the One-Way Active Measurement Protocol (OWAMP) and Two-Way Active Measurement Protocol (TWAMP)" [RFC7717], "Well-Known Port Assignments for the One-Way Active Measurement Protocol (OWAMP) and the Two-Way Active Measurement Protocol (TWAMP)" [RFC8545], and "Registry for Performance Metrics" [RFC8911].¶
<CODE BEGINS> file "ietf-twamp@2021-11-17.yang"
module ietf-twamp {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-twamp";
prefix ietf-twamp;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
organization
"IETF IPPM (IP Performance Metrics) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/ippm/documents/>
WG List: <mailto:ippm@ietf.org>
Editor: Ruth Civil
<mailto:ruthcivil@gmail.com>
Editor: Al Morton
<mailto:acmorton@att.com>
Editor: Reshad Rahman
<mailto:reshad@yahoo.com>
Editor: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Kostas Pentikousis
<mailto:kostas.pentikousis@detecon.com>";
description
"This YANG module specifies a vendor-independent data
model for the Two-Way Active Measurement Protocol (TWAMP).
The data model defines four TWAMP logical entities, namely
Control-Client, Server, Session-Sender, and Session-Reflector,
as illustrated in the annotated TWAMP logical model (Figure 1
of RFC 8913).
This YANG module uses features to indicate which of the four
logical entities are supported by a TWAMP implementation.
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
'MAY', and 'OPTIONAL' in this document are to be interpreted as
described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.
Copyright (c) 2021 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 8913; see the
RFC itself for full legal notices.";
revision 2021-11-17 {
description
"Initial revision.
References RFC 5357, RFC 5618, RFC 5938, RFC 6038, RFC 7717,
and RFC 8911.";
reference
"RFC 8913: Two-Way Active Measurement Protocol (TWAMP) YANG
Data Model";
}
/*
* Typedefs
*/
typedef twamp-modes {
type bits {
bit unauthenticated {
position 0;
description
"Unauthenticated mode, in which no encryption or
authentication is applied in TWAMP-Control and
TWAMP-Test. KeyID, Token, and Client-IV are not used in
the Set-Up-Response message. See Section 3.1 of
RFC 4656.";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP),
Section 3.1";
}
bit authenticated {
position 1;
description
"Authenticated mode, in which the Control-Client and
Server possess a shared secret, thus prohibiting
'theft of service'. As per Section 6 of RFC 4656,
in 'authenticated mode, the timestamp is in the clear
and is not protected cryptographically in any way,
while the rest of the message has the same protection
as in encrypted mode. This mode allows one to trade off
cryptographic protection against accuracy of
timestamps.'";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP),
Section 6";
}
bit encrypted {
position 2;
description
"Encrypted mode 'makes it impossible to alter
timestamps undetectably' (Section 1 of RFC 4656).
See also Section 4 of RFC 7717.";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP),
Section 6
RFC 7717: IKEv2-Derived Shared Secret Key for the One-Way
Active Measurement Protocol (OWAMP) and Two-Way Active
Measurement Protocol (TWAMP), Section 4";
}
bit unauth-test-encrypt-control {
position 3;
description
"When using the mixed security mode, the TWAMP-Test
protocol operates in unauthenticated mode and the
TWAMP-Control protocol operates in encrypted mode.";
reference
"RFC 5618: Mixed Security Mode for the Two-Way Active
Measurement Protocol (TWAMP)";
}
bit individual-session-control {
position 4;
description
"This mode enables individual test sessions using
Session Identifiers.";
reference
"RFC 5938: Individual Session Control Feature
for the Two-Way Active Measurement Protocol (TWAMP)";
}
bit reflect-octets {
position 5;
description
"This mode indicates the reflect octets capability.";
reference
"RFC 6038: Two-Way Active Measurement Protocol (TWAMP)
Reflect Octets and Symmetrical Size Features";
}
bit symmetrical-size {
position 6;
description
"This mode indicates support for the symmetrical size
sender test packet format.";
reference
"RFC 6038: Two-Way Active Measurement Protocol (TWAMP)
Reflect Octets and Symmetrical Size Features";
}
bit IKEv2Derived {
position 7;
description
"In this mode, the shared key is derived
from an Internet Key Exchange Protocol Version 2 (IKEv2)
security association (SA).";
reference
"RFC 7717: IKEv2-Derived Shared Secret Key for
the One-Way Active Measurement Protocol (OWAMP)
and Two-Way Active Measurement Protocol (TWAMP)";
}
}
description
"Specifies the configurable TWAMP-Modes supported during a
TWAMP-Control connection setup between a Control-Client
and a Server. Section 7 of RFC 7717 summarizes the
'TWAMP-Modes' Registry and points to their
formal specification.";
}
typedef control-client-connection-state {
type enumeration {
enum active {
description
"Indicates an active TWAMP-Control connection to the
Server.";
}
enum idle {
description
"Indicates an idle TWAMP-Control connection to the
Server.";
}
}
description
"Indicates the Control-Client TWAMP-Control connection
state.";
}
typedef test-session-state {
type enumeration {
enum accepted {
value 0;
description
"Indicates an accepted TWAMP-Test session request.";
}
enum failed {
value 1;
description
"Indicates a TWAMP-Test session failure due to
some unspecified reason (catch-all).";
}
enum internal-error {
value 2;
description
"Indicates a TWAMP-Test session failure due to
an internal error.";
}
enum not-supported {
value 3;
description
"Indicates a TWAMP-Test session failure because
some aspect of the TWAMP-Test session request
is not supported.";
}
enum permanent-resource-limit {
value 4;
description
"Indicates a TWAMP-Test session failure due to
permanent resource limitations.";
}
enum temp-resource-limit {
value 5;
description
"Indicates a TWAMP-Test session failure due to
temporary resource limitations.";
}
}
description
"Indicates the Control-Client TWAMP-Test session state.";
}
typedef server-ctrl-connection-state {
type enumeration {
enum active {
description
"Indicates an active TWAMP-Control connection
to the Control-Client.";
}
enum servwait {
description
"Indicates that the TWAMP-Control connection to the
Control-Client is in SERVWAIT as per the definition in
Section 3.1 of RFC 5357.";
reference
"RFC 5357: A Two-Way Active Measurement Protocol (TWAMP),
Section 3.1";
}
}
description
"Indicates the Server TWAMP-Control connection state.";
}
typedef sender-session-state {
type enumeration {
enum active {
description
"Indicates that the TWAMP-Test session is active.";
}
enum failure {
description
"Indicates that the TWAMP-Test session has failed.";
}
}
description
"Indicates the Session-Sender TWAMP-Test session state.";
}
typedef padding-fill-mode {
type enumeration {
enum zero {
description
"TWAMP-Test packets are padded with all zeros.";
}
enum random {
description
"TWAMP-Test packets are padded with pseudorandom
numbers.";
}
}
description
"Indicates what type of packet padding is used in the
TWAMP-Test packets.";
}
typedef dynamic-port-number {
type inet:port-number {
range "49152..65535";
}
description
"Dynamic range for port numbers.";
}
/*
* Features
*/
feature control-client {
description
"Indicates that the device supports configuration of the
TWAMP Control-Client logical entity.";
}
feature server {
description
"Indicates that the device supports configuration of the
TWAMP Server logical entity.";
}
feature session-sender {
description
"Indicates that the device supports configuration of the
TWAMP Session-Sender logical entity.";
}
feature session-reflector {
description
"Indicates that the device supports configuration of the
TWAMP Session-Reflector logical entity.";
}
/*
* Reusable node groups
*/
grouping key-management {
list key-chain {
key "key-id";
leaf key-id {
type string {
length "1..80";
}
description
"KeyID used for a TWAMP-Control connection. As per
Section 3.1 of RFC 4656, KeyID is 'a UTF-8 string, up to
80 octets in length' and is used to select which 'shared
secret the client' (Control-Client) 'wishes to use to
authenticate or encrypt'.";
}
leaf secret-key {
type binary;
description
"The secret key corresponding to the KeyID for this
TWAMP-Control connection.";
}
description
"Relates KeyIDs with their respective secret keys
in a TWAMP-Control connection.";
}
description
"Used by the Control-Client and Server for TWAMP-Control
key management.";
}
grouping maintenance-statistics {
leaf sent-packets {
type uint32;
config false;
description
"Indicates the number of packets sent.";
}
leaf rcv-packets {
type uint32;
config false;
description
"Indicates the number of packets received.";
}
leaf last-sent-seq {
type uint32;
config false;
description
"Indicates the last sent sequence number.";
}
leaf last-rcv-seq {
type uint32;
config false;
description
"Indicates the last received sequence number.";
}
description
"Used for TWAMP-Test maintenance statistics.";
}
grouping count {
leaf count {
type uint8 {
range "10..31";
}
default "15";
description
"Parameter communicated to the Control-Client as part of
the Server Greeting message and used for deriving a key
from a shared secret as per Section 3.1 of RFC 4656:
MUST be a power of 2 and at least 1024. It is configured
by providing said power. For example, configuring 20 here
means count 2^20 = 1048576. The default is 15,
meaning 2^15 = 32768.";
}
description
"Reusable data structure for count, which is used in both the
Server and the Control-Client.";
}
grouping max-count-exponent {
leaf max-count-exponent {
type uint8 {
range "10..31";
}
default "20";
description
"This parameter limits the maximum Count value, which MUST
be a power of 2 and at least 1024 as per RFC 5357. It is
configured by providing said power. For example,
configuring 10 here means max count 2^10 = 1024.
The default is 20, meaning 2^20 = 1048576.
A TWAMP Server uses this configured value in the
Server Greeting message sent to the Control-Client.
A TWAMP Control-Client uses this configured value to
prevent denial-of-service (DoS) attacks by closing the
control connection to the Server if it 'receives a
Server-Greeting message with Count greater that [sic] its
maximum configured value', as per Section 6 of RFC 5357.
Further, note that according to Section 6 of RFC 5357:
'If an attacking system set the maximum value in Count
(2**32), then the system under attack would stall for a
significant period of time while it attempts to generate
keys. Therefore, TWAMP-compliant systems SHOULD have a
configuration control to limit the maximum Count value.
The default maximum Count value SHOULD be 32768.'
In the case of this document, the default max-count-exponent
value SHOULD be 15, which corresponds to a maximum value of
2**15 or 32768.
RFC 5357 does not qualify 'significant period' in terms of
time, but it is clear that this depends on the processing
capacity available, and operators need to pay attention to
this security consideration.";
}
description
"Reusable data structure for max-count that is used in both
the client (Control-Client) container and the server
container.";
}
/*
* Configuration data nodes
*/
container twamp {
description
"TWAMP logical entity configuration grouping of four models
that correspond to the four TWAMP logical entities
Control-Client, Server, Session-Sender, and Session-Reflector
as illustrated in Figure 1 of RFC 8913.";
container client {
if-feature "control-client";
description
"Configuration of the TWAMP Control-Client logical entity.";
leaf admin-state {
type boolean;
default "true";
description
"Indicates whether the device is allowed to operate as a
TWAMP Control-Client.";
}
list mode-preference-chain {
key "priority";
unique "mode";
leaf priority {
type uint16;
description
"Indicates the Control-Client mode preference priority,
expressed as a 16-bit unsigned integer. Values for the
priority start with zero, the highest priority, and
decreasing priority value is indicated by every increase
in value by one.";
}
leaf mode {
type twamp-modes;
description
"The supported TWAMP-Modes matching the corresponding
priority.";
}
description
"Indicates the Control-Client preferred order of use of
the supported TWAMP-Modes.
Depending on the modes available in the TWAMP Server
Greeting message (see Figure 2 of RFC 7717), the
Control-Client MUST choose the highest-priority
mode from the configured mode-preference-chain list.";
}
uses key-management;
list ctrl-connection {
key "name";
description
"List of TWAMP Control-Client control connections.
Each item in the list describes a control connection
that will be initiated by this Control-Client.";
leaf name {
type string;
description
"A unique name used as a key to identify this
individual TWAMP-Control connection on the
Control-Client device.";
}
leaf client-ip {
type inet:ip-address;
description
"The IP address of the local Control-Client device,
to be placed in the source IP address field of the
IP header in TWAMP-Control (TCP) packets belonging
to this control connection. If not configured, the
device SHALL choose its own source IP address.";
}
leaf server-ip {
type inet:ip-address;
mandatory true;
description
"The IP address of the remote Server device to which
the TWAMP-Control connection will be initiated.";
}
leaf server-tcp-port {
type inet:port-number;
default "862";
description
"This parameter defines the TCP port number that is
to be used by this outgoing TWAMP-Control connection.
Typically, this is the well-known TWAMP-Control
port number (862) as per RFC 5357. However, there are
known realizations of TWAMP in the field that were
implemented before this well-known port number was
allocated. These early implementations allowed the
port number to be configured. This parameter is
therefore provided for backward-compatibility
reasons.";
}
leaf control-packet-dscp {
type inet:dscp;
default "0";
description
"The Differentiated Services Code Point (DSCP) value
to be placed in the IP header of TWAMP-Control (TCP)
packets generated by this Control-Client.";
}
leaf key-id {
type string {
length "1..80";
}
description
"Indicates the KeyID value selected for this
TWAMP-Control connection.";
}
uses max-count-exponent;
leaf client-tcp-port {
type inet:port-number;
config false;
description
"Indicates the source TCP port number used in the
TWAMP-Control packets belonging to this control
connection.";
}
leaf server-start-time {
type uint64;
config false;
description
"Indicates the Start-Time advertised by the Server in
the Server-Start message (RFC 4656, Section 3.1),
representing the time when the current
instantiation of the Server started operating.
The timestamp format follows RFC 5905, according to
Section 4.1.2 of RFC 4656.";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP),
Sections 3.1 and 4.1.2
RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification";
}
leaf repeat-count {
type uint64;
config false;
description
"Indicates how many times the test session has been
repeated. When a test is running, this value will be
greater than 0. If the repeat parameter is non-zero,
this value is smaller than or equal to the repeat
parameter.";
}
leaf state {
type control-client-connection-state;
config false;
description
"Indicates the current TWAMP-Control connection state.";
}
leaf selected-mode {
type twamp-modes;
config false;
description
"The TWAMP-Modes that the Control-Client has chosen for
this control connection as set in the Mode field of
the Set-Up-Response message.";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP),
Section 3.1";
}
leaf token {
type binary {
length "64";
}
config false;
description
"This parameter holds the 64 octets containing the
concatenation of a 16-octet Challenge, a 16-octet AES
Session-key used for encryption, and a 32-octet
HMAC-SHA1 Session-key used for authentication; see
also the last paragraph of Section 6.10 of RFC 4656.
If the mode defined in RFC 7717 is selected
(selected-mode), Token is limited to 16 octets.";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP),
Section 6.10
RFC 7717: IKEv2-Derived Shared Secret Key for the
One-Way Active Measurement Protocol (OWAMP) and
Two-Way Active Measurement Protocol (TWAMP)";
}
leaf client-iv {
type binary {
length "16";
}
config false;
description
"Indicates the Control-Client Initialization Vector
(Client-IV), which is generated randomly by the
Control-Client. As per RFC 4656:
'Client-IV merely needs to be unique (i.e., it MUST
never be repeated for different sessions using the
same secret key; a simple way to achieve that without
the use of cumbersome state is to generate the
Client-IV values using a cryptographically secure
pseudo-random number source.'
If the mode defined in RFC 7717 is selected
(selected-mode), Client-IV is limited to 12 octets.";
reference
"RFC 4656: A One-way Active Measurement Protocol (OWAMP)
RFC 7717: IKEv2-Derived Shared Secret Key for the
One-Way Active Measurement Protocol (OWAMP) and
Two-Way Active Measurement Protocol (TWAMP)";
}
list test-session-request {
key "name";
description
"Information associated with the Control-Client
for this test session.";
leaf name {
type string;
description
"A unique name to be used for identification of
this TWAMP-Test session on the Control-Client.";
}
leaf sender-ip {
type inet:ip-address;
description
"The IP address of the Session-Sender device,
which is to be placed in the source IP address
field of the IP header in TWAMP-Test (UDP) packets
belonging to this test session. This value will be
used to populate the Sender Address field of the
Request-TW-Session message.
If not configured, the device SHALL choose its own
source IP address.";
}
leaf sender-udp-port {
type union {
type dynamic-port-number;
type enumeration {
enum autoallocate {
description
"Indicates that the Control-Client will
auto-allocate the TWAMP-Test (UDP) port number
from the dynamic port range.";
}
}
}
default "autoallocate";
description
"The UDP port number that is to be used by
the Session-Sender for this TWAMP-Test session.
The number is restricted to the dynamic port range.
By default, the Control-Client SHALL auto-allocate a
UDP port number for this TWAMP-Test session.
The configured (or auto-allocated) value is
advertised in the Sender Port field of the
Request-TW-Session message (see Section 3.5 of
RFC 5357). Note that in the scenario where a device
auto-allocates a UDP port number for a session and
the repeat parameter for that session indicates that
it should be repeated, the device is free to
auto-allocate a different UDP port number when it
negotiates the next (repeated) iteration of this
session.";
}
leaf reflector-ip {
type inet:ip-address;
mandatory true;
description
"The IP address belonging to the remote
Session-Reflector device to which the TWAMP-Test
session will be initiated. This value will be
used to populate the Receiver Address field of
the Request-TW-Session message.";
}
leaf reflector-udp-port {
type inet:port-number {
range "862 | 49152..65535";
}
description
"This parameter defines the UDP port number that
will be used by the Session-Reflector for
this TWAMP-Test session. The default number is
within the dynamic port range and is to be placed
in the Receiver Port field of the Request-TW-Session
message. The well-known port (862) MAY be used.";
reference
"RFC 8545: Well-Known Port Assignments for the One-Way
Active Measurement Protocol (OWAMP) and the Two-Way
Active Measurement Protocol (TWAMP)";
}
leaf timeout {
type uint64;
units "seconds";
default "2";
description
"The length of time (in seconds) that the
Session-Reflector should continue to respond to
packets belonging to this TWAMP-Test session after
a Stop-Sessions TWAMP-Control message has been
received.
This value will be placed in the Timeout field of
the Request-TW-Session message.";
reference
"RFC 5357: A Two-Way Active Measurement Protocol
(TWAMP), Section 3.5";
}
leaf padding-length {
type uint32 {
range "64..4096";
}
description
"The number of padding bytes to be added to the
TWAMP-Test (UDP) packets generated by the
Session-Sender.
This value will be placed in the Padding Length
field of the Request-TW-Session message.";
reference
"RFC 4656: A One-way Active Measurement Protocol
(OWAMP), Section 3.5";
}
leaf test-packet-dscp {
type inet:dscp;
default "0";
description
"The DSCP value to be placed in the IP header
of TWAMP-Test packets generated by the
Session-Sender and in the UDP header of the
TWAMP-Test response packets generated by the
Session-Reflector for this test session.
This value will be placed in the Type-P Descriptor
field of the Request-TW-Session message.";
reference
"RFC 5357: A Two-Way Active Measurement Protocol
(TWAMP)";
}
leaf start-time {
type uint64;
default "0";
description
"Time when the session is to be started
(but not before the TWAMP Start-Sessions command
is issued; see Section 3.4 of RFC 5357).
The start-time value is placed in the Start Time
field of the Request-TW-Session message.
The timestamp format follows RFC 5905 as per
Section 3.5 of RFC 4656.
The default value of 0 indicates that the session
will be started as soon as the Start-Sessions
message is received.";
}
leaf repeat {
type uint32 {
range "0..4294967295";
}
default "0";
description
"This value determines if the TWAMP-Test session must
be repeated. When a test session has completed, the
repeat parameter is checked.
The default value of 0 indicates that the session
MUST NOT be repeated.
If the repeat value is 1 through 4,294,967,294,
then the test session SHALL be repeated using the
information in the repeat-interval parameter, and the
parent TWAMP-Control connection for this test
session is restarted to negotiate a new instance
of this TWAMP-Test session.
A value of 4,294,967,295 indicates that the test
session SHALL be repeated *forever* using the
information in the repeat-interval parameter and
SHALL NOT decrement the value.";
}
leaf repeat-interval {
when "../repeat!='0'" {
description
"This parameter determines the timing of repeated
TWAMP-Test sessions when repeat is more than 0.
When the value of repeat-interval is 0, the
negotiation of a new test session SHALL begin
immediately after the previous test session
completes. Otherwise, the Control-Client will
wait for the number of seconds specified in the
repeat-interval parameter before negotiating the
new instance of this TWAMP-Test session.";
}
type uint32;
units "seconds";
default "0";
description
"Repeat interval (in seconds).";
}
list pm-reg-list {
key "pm-index";
leaf pm-index {
type uint16;
description
"Numerical index value of a Registered Metric in
the Performance Metrics Registry (see RFC 8911).
Output statistics are specified in the
corresponding Registry Entry.";
}
description
"A list of one or more Performance Metrics Registry
Index values, which communicate packet stream
characteristics along with one or more metrics
to be measured.
All members of the pm-reg-list MUST have the same
stream characteristics, such that they combine
to specify all metrics that shall be measured on
a single stream.";
reference
"RFC 8911: Registry for Performance Metrics";
}
leaf state {
type test-session-state;
config false;
description
"Indicates the TWAMP-Test session state -- an accepted
request or an indication of an error.";
reference
"RFC 5357: A Two-Way Active Measurement Protocol
(TWAMP), Section 3.5";
}
leaf sid {
type string;
config false;
description
"The Session Identifier (SID) allocated by the Server
for this TWAMP-Test session and communicated back to
the Control-Client in the SID field of the
Accept-Session message.";
reference
"RFC 6038: Two-Way Active Measurement Protocol (TWAMP)
Reflect Octets and Symmetrical Size
Features, Section 4.3";
}
}
}
}
container server {
if-feature "server";
description
"Configuration of the TWAMP Server logical entity.";
leaf admin-state {
type boolean;
default "true";
description
"Indicates whether the device is allowed to operate
as a TWAMP Server.";
}
leaf server-tcp-port {
type inet:port-number;
default "862";
description
"This parameter defines the well-known TCP port number
that is used by TWAMP-Control. The Server will listen
on this port number for incoming TWAMP-Control
connections. Although this is defined as a fixed value
(862) in RFC 5357, there are several realizations of
TWAMP in the field that were implemented before this
well-known port number was allocated. These early
implementations allowed the port number to be
configured. This parameter is therefore provided for
backward-compatibility reasons.";
}
leaf servwait {
type uint32 {
range "1..604800";
}
units "seconds";
default "900";
description
"TWAMP-Control (TCP) session timeout, in seconds.
According to Section 3.1 of RFC 5357:
'The Server MAY discontinue any established control
connection when no packet associated with that
connection has been received within SERVWAIT seconds.'";
}
leaf control-packet-dscp {
type inet:dscp;
description
"The DSCP value to be placed in the IP header of
TWAMP-Control (TCP) packets generated by the Server.
Section 3.1 of RFC 5357 specifies that the Server
SHOULD use the DSCP value from the Control-Client's
TCP SYN. However, for practical purposes, TWAMP will
typically be implemented using a general-purpose TCP
stack provided by the underlying operating system,
and such a stack may not provide this information to the
user. Consequently, it is not always possible to
implement the behavior described in RFC 5357 in an
OS-portable version of TWAMP.
The default behavior if this item is not set is to use
the DSCP value from the Control-Client's TCP SYN.";
reference
"RFC 5357: A Two-Way Active Measurement Protocol (TWAMP),
Section 3.1";
}
uses count;
uses max-count-exponent;
leaf modes {
type twamp-modes;
description
"The bit mask of TWAMP-Modes this Server instance is
willing to support; see the IANA 'TWAMP-Modes' Registry.";
}
uses key-management;
list ctrl-connection {
key "client-ip client-tcp-port server-ip server-tcp-port";
config false;
description
"List of all incoming TWAMP-Control (TCP) connections.";
leaf client-ip {
type inet:ip-address;
description
"The IP address on the remote Control-Client device,
which is the source IP address used in the
TWAMP-Control (TCP) packets belonging to this control
connection.";
}
leaf client-tcp-port {
type inet:port-number;
description
"The source TCP port number used in the TWAMP-Control
(TCP) packets belonging to this control connection.";
}
leaf server-ip {
type inet:ip-address;
description
"The IP address of the local Server device, which is
the destination IP address used in the
TWAMP-Control (TCP) packets belonging to this control
connection.";
}
leaf server-tcp-port {
type inet:port-number;
description
"The destination TCP port number used in the
TWAMP-Control (TCP) packets belonging to this
control connection. This will usually be the
same value as the server-tcp-port configured
under twamp/server. However, in the event that
the user reconfigured server/server-tcp-port
after this control connection was initiated, this
value will indicate the server-tcp-port that is
actually in use for this control connection.";
}
leaf state {
type server-ctrl-connection-state;
description
"Indicates the Server TWAMP-Control connection state.";
}
leaf control-packet-dscp {
type inet:dscp;
description
"The DSCP value used in the IP header of the
TWAMP-Control (TCP) packets sent by the Server
for this control connection. This will usually
be the same value as is configured in the
control-packet-dscp parameter under the twamp/server
container. However, in the event that the user
reconfigures server/dscp after this control
connection is already in progress, this read-only
value will show the actual DSCP value in use by this
TWAMP-Control connection.";
}
leaf selected-mode {
type twamp-modes;
description
"The mode that was chosen for this TWAMP-Control
connection as set in the Mode field of the
Set-Up-Response message.";
}
leaf key-id {
type string {
length "1..80";
}
description
"The KeyID value that is in use by this TWAMP-Control
connection as selected by the Control-Client.";
}
uses count {
description
"The Count value that is in use by this TWAMP-Control
connection. This will usually be the same value
as is configured under twamp/server. However, in the
event that the user reconfigures server/count
after this control connection is already in progress,
this read-only value will show the actual count that
is in use for this TWAMP-Control connection.";
}
uses max-count-exponent {
description
"This read-only value indicates the actual max-count in
use for this control connection. Usually, this would be
the same value as is configured under twamp/server.";
}
leaf salt {
type binary {
length "16";
}
description
"A parameter used in deriving a key from a
shared secret, as described in Section 3.1 of RFC 4656.
It is communicated to the Control-Client as part of
the Server Greeting message.";
}
leaf server-iv {
type binary {
length "16";
}
description
"The Server Initialization Vector (Server-IV)
generated randomly by the Server.";
}
leaf challenge {
type binary {
length "16";
}
description
"A random sequence of octets generated by the Server.
As described in client/token, a Challenge is used
by the Control-Client to prove possession of a
shared secret.";
}
}
}
container session-sender {
if-feature "session-sender";
description
"Configuration of the TWAMP Session-Sender logical entity.";
leaf admin-state {
type boolean;
default "true";
description
"Indicates whether the device is allowed to operate
as a TWAMP Session-Sender.";
}
list test-session {
key "name";
description
"List of TWAMP Session-Sender test sessions.";
leaf name {
type string;
description
"A unique name for this TWAMP-Test session to be used
for identifying this test session by the
Session-Sender logical entity.";
}
leaf ctrl-connection-name {
type string;
config false;
description
"The name of the parent TWAMP-Control connection that
is responsible for negotiating this TWAMP-Test
session.";
}
leaf fill-mode {
type padding-fill-mode;
default "zero";
description
"Indicates whether the padding added to the
TWAMP-Test (UDP) packets (1) will contain pseudorandom
numbers or (2) should consist of all zeros, as per
Section 4.2.1 of RFC 5357.";
}
leaf number-of-packets {
type uint32;
mandatory true;
description
"The overall number of TWAMP-Test (UDP) packets to be
transmitted by the Session-Sender for this test
session.";
}
choice packet-distribution {
description
"Indicates the distribution to be used for transmitting
the TWAMP-Test (UDP) packets.";
case periodic {
leaf periodic-interval {
type decimal64 {
fraction-digits 5;
}
units "seconds";
mandatory true;
description
"Indicates the time to wait (in seconds) between
the first bits of TWAMP-Test (UDP) packet
transmissions for this test session.";
reference
"RFC 3432: Network performance measurement with
periodic streams";
}
}
case poisson {
leaf lambda {
type decimal64 {
fraction-digits 5;
}
units "seconds";
mandatory true;
description
"Indicates the average time interval (in seconds)
between packets in the Poisson distribution.
The packet is calculated using the reciprocal of
lambda and the TWAMP-Test packet size (which
depends on the selected mode and the packet
padding).";
reference
"RFC 2330: Framework for IP Performance Metrics";
}
leaf max-interval {
type decimal64 {
fraction-digits 5;
}
units "seconds";
description
"Indicates the maximum time (in seconds)
between packet transmissions.";
reference
"RFC 7312: Advanced Stream and Sampling Framework
for IP Performance Metrics (IPPM)";
}
}
}
leaf state {
type sender-session-state;
config false;
description
"Indicates the Session-Sender test session state.";
}
uses maintenance-statistics;
}
}
container session-reflector {
if-feature "session-reflector";
description
"Configuration of the TWAMP Session-Reflector logical
entity.";
leaf admin-state {
type boolean;
default "true";
description
"Indicates whether the device is allowed to operate
as a TWAMP Session-Reflector.";
}
leaf refwait {
type uint32 {
range "1..604800";
}
units "seconds";
default "900";
description
"The Session-Reflector MAY discontinue any session that
has been started when no packet associated with that
session has been received for REFWAIT seconds. As per
Section 3.1 of RFC 5357, this timeout allows a
Session-Reflector to free up resources in case of
failure.";
}
list test-session {
key "sender-ip sender-udp-port
reflector-ip reflector-udp-port";
config false;
description
"TWAMP Session-Reflector test sessions.";
leaf sid {
type string;
description
"An auto-allocated identifier for this TWAMP-Test
session that is unique within the context of this
Server/Session-Reflector device only. This value
is communicated to the Control-Client that
requested the test session in the SID field of the
Accept-Session message.";
}
leaf sender-ip {
type inet:ip-address;
description
"The IP address on the remote device, which is the
source IP address used in the TWAMP-Test (UDP) packets
belonging to this test session.";
}
leaf sender-udp-port {
type dynamic-port-number;
description
"The source UDP port used in the TWAMP-Test packets
belonging to this test session.";
}
leaf reflector-ip {
type inet:ip-address;
description
"The IP address of the local Session-Reflector
device, which is the destination IP address used
in the TWAMP-Test (UDP) packets belonging to this test
session.";
}
leaf reflector-udp-port {
type inet:port-number {
range "862 | 49152..65535";
}
description
"The destination UDP port number used in the
TWAMP-Test (UDP) test packets belonging to this
test session.";
}
leaf parent-connection-client-ip {
type inet:ip-address;
description
"The IP address on the Control-Client device, which
is the source IP address used in the TWAMP-Control
(TCP) packets belonging to the parent control
connection that negotiated this test session.";
}
leaf parent-connection-client-tcp-port {
type inet:port-number;
description
"The source TCP port number used in the TWAMP-Control
(TCP) packets belonging to the parent control
connection that negotiated this test session.";
}
leaf parent-connection-server-ip {
type inet:ip-address;
description
"The IP address of the Server device, which is the
destination IP address used in the TWAMP-Control
(TCP) packets belonging to the parent control
connection that negotiated this test session.";
}
leaf parent-connection-server-tcp-port {
type inet:port-number;
description
"The destination TCP port number used in the
TWAMP-Control (TCP) packets belonging to the parent
control connection that negotiated this test
session.";
}
leaf test-packet-dscp {
type inet:dscp;
description
"The DSCP value present in the IP header of
TWAMP-Test (UDP) packets belonging to this session.";
}
uses maintenance-statistics;
}
}
}
}
<CODE ENDS>6. Data Model Examples
This section presents simple but complete examples of configuring
all four entities in Figure 1, based on the YANG
module specified in Section 5. The
examples are illustrative
in nature but aim to be self-contained, i.e., were they to be executed in
a real TWAMP implementation, they would lead to correctly configured test
sessions. For completeness, examples are provided for both IPv4 and
IPv6. The examples are shown using XML
[W3C
More elaborate examples, which also include authentication parameters, are provided in Appendix A.¶
6.1. Control-Client
Figure 8 shows a configuration example for a
Control-Client with client
<?xml version="1.0" encoding="utf-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<client>
<admin-state>true</admin-state>
</client>
</twamp>
</config>The following example shows a Control-Client with two instances of
client
<?xml version="1.0" encoding="utf-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<client>
<admin-state>true</admin-state>
<ctrl-connection>
<name>RouterA</name>
<client-ip>203.0.113.1</client-ip>
<server-ip>203.0.113.2</server-ip>
<test-session-request>
<name>Test1</name>
<sender-ip>203.0.113.3</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>203.0.113.4</reflector-ip>
<reflector-udp-port>50001</reflector-udp-port>
<start-time>0</start-time>
</test-session-request>
<test-session-request>
<name>Test2</name>
<sender-ip>203.0.113.1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>203.0.113.2</reflector-ip>
<reflector-udp-port>50001</reflector-udp-port>
<start-time>0</start-time>
</test-session-request>
</ctrl-connection>
<ctrl-connection>
<name>RouterB</name>
<client-ip>203.0.113.1</client-ip>
<server-ip>203.0.113.3</server-ip>
</ctrl-connection>
</client>
</twamp>
</config><?xml version="1.0" encoding="utf-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<client>
<admin-state>true</admin-state>
<ctrl-connection>
<name>RouterA</name>
<client-ip>2001:db8:203:0:113::1</client-ip>
<server-ip>2001:db8:203:0:113::2</server-ip>
<test-session-request>
<name>Test1</name>
<sender-ip>2001:db8:203:1:113::3</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>2001:db8:203:1:113::4</reflector-ip>
<reflector-udp-port>55000</reflector-udp-port>
<start-time>0</start-time>
</test-session-request>
<test-session-request>
<name>Test2</name>
<sender-ip>2001:db8:203:0:113::1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>2001:db8:203:0:113::2</reflector-ip>
<reflector-udp-port>55001</reflector-udp-port>
<start-time>0</start-time>
</test-session-request>
</ctrl-connection>
<ctrl-connection>
<name>RouterB</name>
<client-ip>2001:db8:203:0:113::1</client-ip>
<server-ip>2001:db8:203:0:113::3</server-ip>
</ctrl-connection>
</client>
</twamp>
</config>6.2. Server
Figure 9 shows a configuration example for a
Server with server
<?xml version="1.0" encoding="utf-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<server>
<admin-state>true</admin-state>
</server>
</twamp>
</config>The following example presents a Server with the TWAMP-Control
connection corresponding to the control connection name
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<server>
<admin-state>true</admin-state>
<ctrl-connection>
<client-ip>203.0.113.1</client-ip>
<client-tcp-port>16341</client-tcp-port>
<server-ip>203.0.113.2</server-ip>
<server-tcp-port>862</server-tcp-port>
<state>active</state>
</ctrl-connection>
</server>
</twamp>
</data><?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<server>
<admin-state>true</admin-state>
<ctrl-connection>
<client-ip>2001:db8:203:0:113::1</client-ip>
<client-tcp-port>16341</client-tcp-port>
<server-ip>2001:db8:203:0:113::2</server-ip>
<server-tcp-port>862</server-tcp-port>
<state>active</state>
</ctrl-connection>
</server>
</twamp>
</data>6.3. Session-Sender
Figure 10 shows a configuration example for a
Session-Sender with session
<?xml version="1.0" encoding="utf-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-sender>
<admin-state>true</admin-state>
</session-sender>
</twamp>
</config>The following configuration example shows a Session-Sender with the two TWAMP-Test sessions presented in Section 6.1.¶
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-sender>
<admin-state>true</admin-state>
<test-session>
<name>Test1</name>
<ctrl-connection-name>RouterA</ctrl-connection-name>
<number-of-packets>900</number-of-packets>
<periodic-interval>1</periodic-interval>
</test-session>
<test-session>
<name>Test2</name>
<ctrl-connection-name>RouterA</ctrl-connection-name>
<number-of-packets>900</number-of-packets>
<lambda>1</lambda>
<max-interval>2</max-interval>
</test-session>
</session-sender>
</twamp>
</data>
6.4. Session-Reflector
This configuration example shows a Session
<?xml version="1.0" encoding="utf-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-reflector>
<admin-state>true</admin-state>
</session-reflector>
</twamp>
</config>The following example shows the two Session
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-reflector>
<admin-state>true</admin-state>
<test-session>
<sender-ip>203.0.113.3</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>203.0.113.4</reflector-ip>
<reflector-udp-port>50001</reflector-udp-port>
<sid>1232</sid>
<parent-connection-client-ip>203.0.113.1</parent-connection-\
client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>203.0.113.2</parent-connection-\
server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<sent-packets>2</sent-packets>
<rcv-packets>2</rcv-packets>
<last-sent-seq>1</last-sent-seq>
<last-rcv-seq>1</last-rcv-seq>
</test-session>
<test-session>
<sender-ip>203.0.113.1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>192.0.2.2</reflector-ip>
<reflector-udp-port>50001</reflector-udp-port>
<sid>178943</sid>
<parent-connection-client-ip>203.0.113.1</parent-connection-\
client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>203.0.113.2</parent-connection-\
server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<sent-packets>21</sent-packets>
<rcv-packets>21</rcv-packets>
<last-sent-seq>20</last-sent-seq>
<last-rcv-seq>20</last-rcv-seq>
</test-session>
</session-reflector>
</twamp>
</data><?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-reflector>
<admin-state>true</admin-state>
<test-session>
<sender-ip>203.0.113.3</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>203.0.113.4</reflector-ip>
<reflector-udp-port>54001</reflector-udp-port>
<sid>1232</sid>
<parent-connection-client-ip>203.0.113.1</parent-connection-\
client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>203.0.113.2</parent-connection-\
server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<sent-packets>2</sent-packets>
<rcv-packets>2</rcv-packets>
<last-sent-seq>1</last-sent-seq>
<last-rcv-seq>1</last-rcv-seq>
</test-session>
<test-session>
<sender-ip>203.0.113.1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>192.0.2.2</reflector-ip>
<reflector-udp-port>55001</reflector-udp-port>
<sid>178943</sid>
<parent-connection-client-ip>203.0.113.1</parent-connection-\
client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>203.0.113.2</parent-connection-\
server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<sent-packets>21</sent-packets>
<rcv-packets>21</rcv-packets>
<last-sent-seq>20</last-sent-seq>
<last-rcv-seq>20</last-rcv-seq>
</test-session>
</session-reflector>
</twamp>
</data>7. Security Considerations
Virtually all existing measurement systems using TWAMP [RFC5357] are administered by the same network operator. For example, attacks on the measurement infrastructure could be launched by third parties to commandeer the packet generation capability, corrupt the measurements, or perform other nefarious acts.¶
The YANG module specified in this document
defines a schema for data that is designed to be accessed via network
management protocols such as NETCONF [RFC6241] or
RESTCONF [RFC8040]. The lowest
NETCONF layer is the secure transport layer, and
the mandatory
The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.¶
There are a number of data nodes defined in this YANG module that are
writable
- If written, the 'admin-state' node can cause unintended test sessions to be created.¶
- If the node 'number
-of -packets', which dictates how many packets are sent in any particular test session, is written with a large value, it can cause a test session to run longer than expected.¶ - Nodes that are particularly vulnerable include several timeout values
put in the protocol to protect against sessions that are not active but
are consuming resources. These are the REFWAIT timeout parameter, which
determines whether to discontinue the session if no packets are received;
and the nodes 'count' and 'max
-count -exponent', which can cause a long time to be spent on Password-Based Key Derivation Function 2 (PBKDF2) iterations.¶ - In addition, a 'dscp' node marked with different DSCP markings can cause the test traffic on the network to be skewed and the result manipulated.¶
- Finally, nodes within 'mode
-preference -chain', which specifies the 'mode' and 'priority' values and indicates the preferred order of use by an operator, can be manipulated to send unauthenticated or non-encrypted traffic, enabling an on-path attack.¶ - Limiting access to these nodes will limit the ability to launch an attack in network environments.¶
Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. This is the subtree and data node
and its sensitivity
- The 'token' node defined in the model, containing a concatenation of a Challenge, an AES Session-key used for encryption, and an HMAC-SHA1 Session-key used for authentication, is sensitive from a privacy perspective and can be used to disrupt a test session. The ability to read the field should be limited to the administrator of the test network.¶
The TWAMP YANG data model does not define RPC operations, as detailed in Appendix B, and defers the definition of NETCONF RPC operations to each implementation. These RPC operations, when defined, may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations.¶
8. IANA Considerations
IANA has registered the following URI in the "IETF XML Registry" [RFC3688].¶
- URI:
- urn
:ietf :params :xml :ns :yang :ietf -twamp¶ - Registrant Contact:
- The IESG.¶
- XML:
- N/A; the requested URI is an XML namespace.¶
IANA has registered the following YANG module in the "YANG Module Names" registry [RFC6020].¶
9. References
9.1. Normative References
- [RFC2119]
-
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10
.17487 , , <https:///RFC2119 www >..rfc -editor .org /info /rfc2119 - [RFC3432]
-
Raisanen, V., Grotefeld, G., and A. Morton, "Network performance measurement with periodic streams", RFC 3432, DOI 10
.17487 , , <https:///RFC3432 www >..rfc -editor .org /info /rfc3432 - [RFC3688]
-
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10
.17487 , , <https:///RFC3688 www >..rfc -editor .org /info /rfc3688 - [RFC4086]
-
Eastlake 3rd, D., Schiller, J., and S. Crocker, "Randomness Requirements for Security", BCP 106, RFC 4086, DOI 10
.17487 , , <https:///RFC4086 www >..rfc -editor .org /info /rfc4086 - [RFC4656]
-
Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. Zekauskas, "A One-way Active Measurement Protocol (OWAMP)", RFC 4656, DOI 10
.17487 , , <https:///RFC4656 www >..rfc -editor .org /info /rfc4656 - [RFC5357]
-
Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", RFC 5357, DOI 10
.17487 , , <https:///RFC5357 www >..rfc -editor .org /info /rfc5357 - [RFC5905]
-
Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10
.17487 , , <https:///RFC5905 www >..rfc -editor .org /info /rfc5905 - [RFC6020]
-
Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10
.17487 , , <https:///RFC6020 www >..rfc -editor .org /info /rfc6020 - [RFC6038]
-
Morton, A. and L. Ciavattone, "Two-Way Active Measurement Protocol (TWAMP) Reflect Octets and Symmetrical Size Features", RFC 6038, DOI 10
.17487 , , <https:///RFC6038 www >..rfc -editor .org /info /rfc6038 - [RFC6241]
-
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10
.17487 , , <https:///RFC6241 www >..rfc -editor .org /info /rfc6241 - [RFC6242]
-
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10
.17487 , , <https:///RFC6242 www >..rfc -editor .org /info /rfc6242 - [RFC6991]
-
Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10
.17487 , , <https:///RFC6991 www >..rfc -editor .org /info /rfc6991 - [RFC7717]
-
Pentikousis, K., Ed., Zhang, E., and Y. Cui, "IKEv2-Derived Shared Secret Key for the One-Way Active Measurement Protocol (OWAMP) and Two-Way Active Measurement Protocol (TWAMP)", RFC 7717, DOI 10
.17487 , , <https:///RFC7717 www >..rfc -editor .org /info /rfc7717 - [RFC7950]
-
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10
.17487 , , <https:///RFC7950 www >..rfc -editor .org /info /rfc7950 - [RFC8040]
-
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10
.17487 , , <https:///RFC8040 www >..rfc -editor .org /info /rfc8040 - [RFC8174]
-
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10
.17487 , , <https:///RFC8174 www >..rfc -editor .org /info /rfc8174 - [RFC8341]
-
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10
.17487 , , <https:///RFC8341 www >..rfc -editor .org /info /rfc8341 - [RFC8446]
-
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10
.17487 , , <https:///RFC8446 www >..rfc -editor .org /info /rfc8446 - [RFC8545]
-
Morton, A., Ed. and G. Mirsky, Ed., "Well-Known Port Assignments for the One-Way Active Measurement Protocol (OWAMP) and the Two-Way Active Measurement Protocol (TWAMP)", RFC 8545, DOI 10
.17487 , , <https:///RFC8545 www >..rfc -editor .org /info /rfc8545 - [RFC8911]
-
Bagnulo, M., Claise, B., Eardley, P., Morton, A., and A. Akhter, "Registry for Performance Metrics", RFC 8911, DOI 10
.17487 , , <https:///RFC8911 www >..rfc -editor .org /info /rfc8911 - [UML]
- ISO/IEC, "Information technology - Open Distributed Processing - Unified Modeling Language (UML) Version 1.4.2", ISO/IEC 19501:2005, OMG-UML VER 1.3, .
- [W3C
.REC -xml -20081126] -
Bray, T., Paoli, J., Sperberg
-Mc , Maler, E., and F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth Edition)", World Wide Web Consortium Recommendation RECQueen, M. -xml , , <https://-20081126 www >..w3 .org /TR /2008 /REC -xml -20081126
9.2. Informative References
- [NSC]
-
John, W., Pentikousis, K., Agapiou, G., Jacob, E., Kind, M., Manzalini, A., Risso, F., Staessens, D., Steinert, R., and C. Meirosu, "Research directions in network service chaining", 2013 IEEE SDN for Future Networks and Services
(SDN4FNS), Trento, Italy, DOI 10
.1109 , , <https:///SDN4FNS .2013 .6702549 doi >..org /10 .1109 /SDN4FNS .2013 .6702549 - [PERF-METRICS]
-
IANA, "Performance Metrics", <https://
www >..iana .org /assignments /performance -metrics - [RFC2330]
-
Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, DOI 10
.17487 , , <https:///RFC2330 www >..rfc -editor .org /info /rfc2330 - [RFC5618]
-
Morton, A. and K. Hedayat, "Mixed Security Mode for the Two-Way Active Measurement Protocol (TWAMP)", RFC 5618, DOI 10
.17487 , , <https:///RFC5618 www >..rfc -editor .org /info /rfc5618 - [RFC5938]
-
Morton, A. and M. Chiba, "Individual Session Control Feature for the Two-Way Active Measurement Protocol (TWAMP)", RFC 5938, DOI 10
.17487 , , <https:///RFC5938 www >..rfc -editor .org /info /rfc5938 - [RFC7312]
-
Fabini, J. and A. Morton, "Advanced Stream and Sampling Framework for IP Performance Metrics (IPPM)", RFC 7312, DOI 10
.17487 , , <https:///RFC7312 www >..rfc -editor .org /info /rfc7312 - [RFC7426]
-
Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis, S., Hadi Salim, J., Meyer, D., and O. Koufopavlou, "Software
-Defined Networking (SDN): Layers and Architecture Terminology" , RFC 7426, DOI 10.17487 , , <https:///RFC7426 www >..rfc -editor .org /info /rfc7426 - [RFC8018]
-
Moriarty, K., Ed., Kaliski, B., and A. Rusch, "PKCS #5: Password-Based Cryptography Specification Version 2.1", RFC 8018, DOI 10
.17487 , , <https:///RFC8018 www >..rfc -editor .org /info /rfc8018 - [RFC8340]
-
Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10
.17487 , , <https:///RFC8340 www >..rfc -editor .org /info /rfc8340 - [RFC8342]
-
Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10
.17487 , , <https:///RFC8342 www >..rfc -editor .org /info /rfc8342
Appendix A. Detailed Data Model Examples
This appendix extends the examples presented in Section 6 by configuring more fields, such as authentication parameters, DSCP values, and so on.¶
A.1. Control-Client
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<client>
<admin-state>true</admin-state>
<mode-preference-chain>
<priority>0</priority>
<mode>authenticated</mode>
</mode-preference-chain>
<mode-preference-chain>
<priority>1</priority>
<mode>unauthenticated</mode>
</mode-preference-chain>
<key-chain>
<key-id>KeyClient1ToRouterA</key-id>
<secret-key>c2VjcmV0MQ==</secret-key>
</key-chain>
<key-chain>
<key-id>KeyForRouterB</key-id>
<secret-key>c2VjcmV0Mg0K</secret-key>
</key-chain>
<ctrl-connection>
<name>RouterA</name>
<client-ip>203.0.113.1</client-ip>
<server-ip>203.0.113.2</server-ip>
<control-packet-dscp>32</control-packet-dscp>
<key-id>KeyClient1ToRouterA</key-id>
<test-session-request>
<name>Test1</name>
<sender-ip>203.0.113.3</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>203.0.113.4</reflector-ip>
<reflector-udp-port>55000</reflector-udp-port>
<padding-length>64</padding-length>
<start-time>0</start-time>
</test-session-request>
<test-session-request>
<name>Test2</name>
<sender-ip>203.0.113.1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>203.0.113.2</reflector-ip>
<reflector-udp-port>55001</reflector-udp-port>
<padding-length>128</padding-length>
<start-time>0</start-time>
</test-session-request>
</ctrl-connection>
</client>
</twamp>
</data><?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<client>
<admin-state>true</admin-state>
<mode-preference-chain>
<priority>0</priority>
<mode>authenticated</mode>
</mode-preference-chain>
<mode-preference-chain>
<priority>1</priority>
<mode>unauthenticated</mode>
</mode-preference-chain>
<key-chain>
<key-id>KeyClient1ToRouterA</key-id>
<secret-key>c2VjcmV0MQ==</secret-key>
</key-chain>
<key-chain>
<key-id>KeyForRouterB</key-id>
<secret-key>c2VjcmV0Mg0K</secret-key>
</key-chain>
<ctrl-connection>
<name>RouterA</name>
<client-ip>2001:db8:203:0:113::1</client-ip>
<server-ip>2001:db8:203:0:113::2</server-ip>
<control-packet-dscp>32</control-packet-dscp>
<key-id>KeyClient1ToRouterA</key-id>
<test-session-request>
<name>Test1</name>
<sender-ip>2001:db8:10:1:1::1</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>2001:db8:10:1:1::2</reflector-ip>
<reflector-udp-port>55000</reflector-udp-port>
<padding-length>64</padding-length>
<start-time>0</start-time>
</test-session-request>
<test-session-request>
<name>Test2</name>
<sender-ip>2001:db8:203:0:113::1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>2001:db8:203:0:113::2</reflector-ip>
<reflector-udp-port>55001</reflector-udp-port>
<padding-length>128</padding-length>
<start-time>0</start-time>
</test-session-request>
</ctrl-connection>
</client>
</twamp>
</data>A.2. Server
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<server>
<admin-state>true</admin-state>
<servwait>1800</servwait>
<control-packet-dscp>32</control-packet-dscp>
<modes>authenticated unauthenticated</modes>
<count>15</count>
<key-chain>
<key-id>KeyClient1ToRouterA</key-id>
<secret-key>c2VjcmV0MQ==</secret-key>
</key-chain>
<key-chain>
<key-id>KeyClient10ToRouterA</key-id>
<secret-key>c2VjcmV0MTANCg==</secret-key>
</key-chain>
<ctrl-connection>
<client-ip>203.0.113.1</client-ip>
<client-tcp-port>16341</client-tcp-port>
<server-ip>203.0.113.2</server-ip>
<server-tcp-port>862</server-tcp-port>
<control-packet-dscp>32</control-packet-dscp>
<selected-mode>unauthenticated</selected-mode>
<key-id>KeyClient1ToRouterA</key-id>
<count>15</count>
</ctrl-connection>
</server>
</twamp>
</data><?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<server>
<admin-state>true</admin-state>
<servwait>1800</servwait>
<control-packet-dscp>32</control-packet-dscp>
<modes>authenticated unauthenticated</modes>
<count>15</count>
<key-chain>
<key-id>KeyClient1ToRouterA</key-id>
<secret-key>c2VjcmV0MQ==</secret-key>
</key-chain>
<key-chain>
<key-id>KeyClient10ToRouterA</key-id>
<secret-key>c2VjcmV0MTANCg==</secret-key>
</key-chain>
<ctrl-connection>
<client-ip>2001:db8:203:0:113::1</client-ip>
<client-tcp-port>16341</client-tcp-port>
<server-ip>2001:db8:203:0:113::2</server-ip>
<server-tcp-port>862</server-tcp-port>
<control-packet-dscp>32</control-packet-dscp>
<selected-mode>unauthenticated</selected-mode>
<key-id>KeyClient1ToRouterA</key-id>
<count>15</count>
</ctrl-connection>
</server>
</twamp>
</data>A.3. Session-Sender
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-sender>
<admin-state>true</admin-state>
<test-session>
<name>Test1</name>
<ctrl-connection-name>RouterA</ctrl-connection-name>
<fill-mode>zero</fill-mode>
<number-of-packets>900</number-of-packets>
<periodic-interval>1</periodic-interval>
<sent-packets>2</sent-packets>
<rcv-packets>2</rcv-packets>
<last-sent-seq>1</last-sent-seq>
<last-rcv-seq>1</last-rcv-seq>
</test-session>
<test-session>
<name>Test2</name>
<ctrl-connection-name>RouterA</ctrl-connection-name>
<fill-mode>random</fill-mode>
<number-of-packets>900</number-of-packets>
<lambda>1</lambda>
<max-interval>2</max-interval>
<sent-packets>21</sent-packets>
<rcv-packets>21</rcv-packets>
<last-sent-seq>20</last-sent-seq>
<last-rcv-seq>20</last-rcv-seq>
</test-session>
</session-sender>
</twamp>
</data>
A.4. Session-Reflector
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-reflector>
<admin-state>true</admin-state>
<test-session>
<sender-ip>203.0.113.3</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>203.0.113.4</reflector-ip>
<reflector-udp-port>55000</reflector-udp-port>
<sid>1232</sid>
<parent-connection-client-ip>203.0.113.1</parent-connection-\
client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>203.0.113.2</parent-connection-\
server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<test-packet-dscp>32</test-packet-dscp>
<sent-packets>2</sent-packets>
<rcv-packets>2</rcv-packets>
<last-sent-seq>1</last-sent-seq>
<last-rcv-seq>1</last-rcv-seq>
</test-session>
<test-session>
<sender-ip>203.0.113.1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>192.0.2.2</reflector-ip>
<reflector-udp-port>55001</reflector-udp-port>
<sid>178943</sid>
<parent-connection-client-ip>203.0.113.1</parent-connection-\
client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>203.0.113.2</parent-connection-\
server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<test-packet-dscp>32</test-packet-dscp>
<sent-packets>21</sent-packets>
<rcv-packets>21</rcv-packets>
<last-sent-seq>20</last-sent-seq>
<last-rcv-seq>20</last-rcv-seq>
</test-session>
</session-reflector>
</twamp>
</data><?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<twamp xmlns="urn:ietf:params:xml:ns:yang:ietf-twamp">
<session-reflector>
<admin-state>true</admin-state>
<test-session>
<sender-ip>2001:db8:10:1:1::1</sender-ip>
<sender-udp-port>54000</sender-udp-port>
<reflector-ip>2001:db8:10:1:1::2</reflector-ip>
<reflector-udp-port>55000</reflector-udp-port>
<sid>1232</sid>
<parent-connection-client-ip>2001:db8:203:0:113::1</parent-c\
onnection-client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>2001:db8:203:0:113::2</parent-c\
onnection-server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<test-packet-dscp>32</test-packet-dscp>
<sent-packets>2</sent-packets>
<rcv-packets>2</rcv-packets>
<last-sent-seq>1</last-sent-seq>
<last-rcv-seq>1</last-rcv-seq>
</test-session>
<test-session>
<sender-ip>2001:db8:203:0:113::1</sender-ip>
<sender-udp-port>54001</sender-udp-port>
<reflector-ip>2001:db8:192:68::2</reflector-ip>
<reflector-udp-port>55001</reflector-udp-port>
<sid>178943</sid>
<parent-connection-client-ip>2001:db8:203:0:113::1</parent-c\
onnection-client-ip>
<parent-connection-client-tcp-port>16341</parent-connection-\
client-tcp-port>
<parent-connection-server-ip>2001:db8:203:0:113::2</parent-c\
onnection-server-ip>
<parent-connection-server-tcp-port>862</parent-connection-se\
rver-tcp-port>
<test-packet-dscp>32</test-packet-dscp>
<sent-packets>21</sent-packets>
<rcv-packets>21</rcv-packets>
<last-sent-seq>20</last-sent-seq>
<last-rcv-seq>20</last-rcv-seq>
</test-session>
</session-reflector>
</twamp>
</data>Appendix B. TWAMP Operational Commands
TWAMP operational commands could be performed programmaticall
With respect to programmability
However, TWAMP [RFC5357] does not attempt to describe such operational actions. Refer also to Section 2 and the unlabeled links in Figure 1. In actual deployments, different TWAMP implementations may support different sets of operational commands, with different restrictions. Therefore, this document considers it the responsibility of the individual implementation to define its corresponding data model for TWAMP operational commands.¶
Acknowledgments
We thank Fred Baker, Kevin D'Souza, Gregory Mirsky, Brian Trammell, Robert Sherman, and Marius Georgescu for their thorough and constructive reviews, comments, and text suggestions.¶
Haoxing Shen contributed to the definition of the YANG module in Section 5.¶
Jan Lindblad and Ladislav Lhotka did thorough reviews of the YANG module and the examples in Appendix A.¶
Kostas Pentikousis was partially supported by FP7 UNIFY, a research project partially funded by the European Community under the Seventh Framework Program (grant agreement no. 619609). The views expressed here are those of the authors only. The European Commission is not liable for any use that may be made of the information in this document.¶
Contributors
Lianshu Zheng¶