RFC Editor Abbreviations List September 2011 ---------------------------------------------------------------------- It is common in technical writing to abbreviate complex technical terms by combining the first letters. The resulting abbreviations are often called acronyms. Editorial guidelines for the RFC series generally require expansion of these abbreviations on first occurrence in a title, in an abstract, or in the body of the document. The RFC Editor attempts to keep the use of abbreviations consistent and to point out conflicts to authors. For this purpose, we have built the abbreviation list below. This list contains abbreviations appearing in RFCs and often reflects discussions with authors, WG chairs, and/or ADs. There is no claim of completeness. Note that some abbreviations have multiple expansions. Some abbreviations are so well known that expansion is probably unnecessary. The RFC Editor exercises editorial judgment about whether a particular use of one of the "well-known" abbreviations requires expansion. (For example, strict adherence to the expansion requirement can lead to impossibly ugly titles.) In the following list of abbreviations, those that are usually (but not necessarily) treated as "well known" are marked with asterisks. However, since there are so many different abbreviations and there is a range of knowledge among RFC readers, we tend to expand abbreviations in case of doubt. Finally, this list includes some terms that look like abbreviations but are actually fixed names for things, and hence cannot and should not be expanded. These are noted as "No expansion". ---------------------------------------------------------------------- 2G - Second generation cellular (mobile) (2G) 2.5G - Enhanced second generation cellular (mobile) (2.5G) 3G - Third generation cellular (mobile) (3G) 3PCC - Third Party Call Control (3PCC) 3GPP IMS - Third Generation Partnership Project Internet Multimedia System or - Third Generation Partnership Project IP Multimedia Subsystem 4rd - IPv4 Residual Deployment 6LSA - IPv6 Label Switching Architecture (6LSA) 6PE - IPv6 Provider Edge (6PE) 6rd - IPv6 Rapid Deployment on IPv4 Infrastructures A+P - Address plus Port AAA - Authentication, Authorization, and Accounting (AAA) AAC - Advanced Audio Coding (AAC) AAD - additional authenticated data (AAD) AAL5 - ATM Adaptation Layer 5 (AAL5) *ABNF - Augmented Backus-Naur form ABR - Area Border Router (ABR) AC - Access Controller (AC) or Attachment Circuit (AC) ACAP - Application Configuration Access Protocol ACH - Associated Channel Header ACK - No Expansion (not an abbreviation) ACL - Access Control List (ACL) ADISC - Address Discovery Extended Link Service (ADISC) Pronounced "ay-disk". ADM - Add-Drop Multiplexer (as in SONET ADM) ADMD - ADministrative Management Domain ADS - Astrophysics Data System (ADS) ADSL - Asymmetric Bit-Rate DSL (ADSL) ADU - Application Data Unit (ADU) AEAD - Authenticated Encryption with Associated Data (AEAD) *AES - Advanced Encryption Standard (AES) AF - Assured Forwarding (as in "Diffserv AF") AFBR - Address Family Border Router (AFBR) AFI - Address Family Identifier (AFI) *AfriNIC - African Network Information Center *AFS - Authentication File System Typically not expanded Proper name is now AFS; expansion name dropped in the 1990s AFTR - Address Family Transition Router (AFTR) AH - Authentication Header (AH) AIMD - Additive Increase Multiplicative Decrease (AIMD) AIS - Alarm Indication Signal (AIS) AKA - Authentication and Key Agreement (AKA) AMI - Advanced Metering Infrastructure (AMI) AKM - Authentication and Key Management (AKM) ALC - Asynchronous Layered Coding (ALC) ALG - Application Level Gateway (ALG) or Application Layer Gateway (ALG) ALOC - Area Locator (ALOC) AMEI - Association of Musical Electronics Industry (AMEI) AMID - Additive Increase Multiplicative Decrease (AMID) AMR - Adaptive Multi Rate (AMR) AMR-WB - Adaptive Multi Rate - WideBand (AMR-WB) AMS - authoritative mapping server (AMS) ANG - Access Network Gateway (ANG) *ANSI - American National Standards Institute AOR - address of record (AOR) AP - Access Point (AP) *API - Application Programming Interface APM - Application Performance Measurement (APM) APN - Access Point Name (APN) *APNIC - Asia Pacific Network Information Centre AR - Address Resolution (AR) *ARIN - American Registry for Internet Numbers ARP - Address Resolution Protocol (ARP) ARQ - Automatic Repeat reQuest AS - Autonomous System (AS) or Applicability Statement (AS) or Authentication Service (AS) or Application Specific (AS) ASBR - Autonomous System Border Router (ASBR) *ASCII - American Standard Code for Information Interchange ASE - Autonomous System External (ASE) or amplifier spontaneous emission (ASE) ASIC - Application-specific Integrated Circuit (ASIC) ASM - Any-Source Multicast (ASM) ASN - Acess Service Network (ASN) *ASN.1 - Abstract Syntax Notation One ASON - Automatically Switched Optical Network ATA - Analog Telephone Adaptor (ATA) ATD - Activation Time Delay (ATD) *ATM - Asynchronous Transfer Mode (ATM) or Automatic Teller Machine (ATM) ATU - ADSL Transceiver Unit (ATU) AU - Access Unit (AU) AUID - Agent or User Identifier (AUID) AVA - Attribute Value Assertion (AVA) AVP - attribute-value pair (AVP) - Audio-Visual Profile (AVP) AVPF - Audio-Visual Profile with Feedback (AVPF) AVT - Audio/Video Transport AXFR - Asynchronous Full Transfer (AXFR) or - Authoritative Transfer or - full zone transfer (AXFR) B2BUA - back-to-back user agent (B2BUA) B4 - Basic Bridging BroadBand (B4) BAB - Bundle Authentication Block (BAB) BB - Bottleneck Bandwidth (BB) *BCH - Bose, Ray-Chaudhuri, Hocquenghem Typically not expanded; as in "BCH code" BCP - Best Current Practice (BCP) or - Bridging Control Protocol (BCP) BDP - Bandwidth-Delay Product (BDP) BECN - Backward Explicit Congestion Notification (BECN) BEEP - Blocks Extensible Exchange Protocol (BEEP) BEK - bundle encryption key (BEK) BER - Basic Encoding Rules (*) bit error rate (BER) BFCP - Binary Floor Control Protocol (BFCP) BFD - Bidirectional Forwarding Detection (BFD) *BGP - Border Gateway Protocol B-ISDN - Broadband Integrated Services Digital Network (B-ISDN) BN - Bundle Node (BN) *BNF - Backus-Naur form BNG - Broadband Network Gateway (BNG) *BOF - Birds of a Feather BPDU - Bridge PDU (BPDU) BR - Border Router (BR) BRAS - Broadband Remote Access Server (BRAS) BRDP - Border Router Discovery Protocol (BRDP) BRI - Basic Rate Interface (BRI) BRPC - Backward Recursive Path Computation (BRPC) Backward Recursive PCE-Based Computation (BRPC) BS - Base Station (BS) *BSD - [name of operating system; better known by acronym] BSM - Bootstrap Message (BSM) BSO - Basic Security Option (BSO) BSP - Bundle Security Protocol (BSP) BSR - Bootstrap Router (BSR) BSSID - Basic Service Set Identifier (BSSID) BTMM - Back to My Mac (BTMM) CA - certification authority (CA) CA - cryptographic authentication (CA) CAC - Connection Admission Control (CAC) CAdES - CMS Advanced Electronic Signatures (CAdES) CALS - Computer-Aided Acquisition and Life-Cycle Support (CALS) CAM - Content Addressable Memory (CAM) captcha - Completely Automated Public Turing test to tell Computers and Humans Apart (captcha) CAPWAP - Control and Provisioning of Wireless Access Points (CAPWAP) CAR - Committed Access Rate (CAR) CARD - Candidate Access Router Discovery (CARD) CATNIP - Common Architecture for Next Generation Internet Protocol (CATNIP) CAVE - Cellular Authentication and Voice Encryption (CAVE) CBC - Cipher Block Chaining (CBC) CBC-MAC - Cipher Block Chaining Message Authentication Code (CBC-MAC) CBID - Crypto-Based Identifier (CBID) CBR - Constant Bitrate (CBR) CC-V - Continuity Check and Connectivity Verification (CC-V) CCID - Congestion Control Identifier (CCID) CCM - Counter with CBC-MAC (CCM) Codec Control Messages (CCM) CCMP - Counter Mode with CBC-MAC Protocol (CCMP) ccTLD - Country Code Top Level Domain (ccTLD) CCXML - Call Control XML (CCXML) CDF - Comma-Delimited Format or - cumulative distribution function (CDF) *CDMA - Code Division Multiple Access CDMA2000 - No Expansion It is a registered trademark of the Telecommunications Industry Association in the US. CDN - Call-Disconnect-Notify (CDN) CDP - Content Delivery Protocol (CDP) CE - Congestion Experienced (CE) or - Customer Edge (CE) - Control Element (CE) CELP - Coded Excited Linear Prediction (CELP) CEP - Circuit Emulation over Packet (CEP) CES - Circuit Emulation Service (CES) - Core-Edge Separation (CES) CFB - Cipher FeedBack (CFB) CFWS - comments and/or folding white space (CFWS) CGA - Cryptographically Generated Addresses (CGA) CGI - Common Gateway Interface (CGI) CGN - Carrier-Grade NAT (CGN) CHAP - Challenge Handshake Authentication Protocol (CHAP) CHbH - Critical Hop-by-Hop (CHbH) CIA - Confidentiality, Integrity, and Availability (CIA) CID - Connection Identifier (CID) Content Identifier (CID) Context Identifier (CID) CIDR - Classless Inter-Domain Routing (CIDR) CIPID - Contact Information in PIDF (CIPID) CIPSO - Common Internet Protocol Security Option (CIPSO) CIS - Cryptographic Interoperability Strategy (CIS) CISC - Complex Instruction Set Computer (or Computing) CItE - Critical Ingress-to-Egress (CItE) CLEI - Common Language Equipment Identifier (CLEI) CLI - command line interface (CLI) or - Call Level Interface (CLI) - Calling Line Identification (CLI) CLNP - Connectionless Network Protocol (CLNP) CLNS - Connectionless Network Service (CLNS) CLP - Cell Loss Priority (CLP) A flag in an ATM cell. CMC - Certificate Management over CMS (CMC) CMS - Cryptographic Message Syntax (CMS) CMTS - cable modem termination system (CMTS) CN - Client Node (CN) or correspondent node (CN) or Common Name (CN) CNG - comfort noise generation (CNG) CoA - Care-of Address (CoA) COM - Component Object Module (COM) COPS - Common Open Policy Service (COPS) Corba - common object request broker architecture (Corba) CoS - Class of Service (CoS) CPE - Customer Premises Equipment (CPE) CPL - Call Processing Language (CPL) CR - carriage return (CR) CRC - Cyclic Redundancy Check (CRC) CR-LDP - Constraint-based Routed Label Distribution Protocol (CR-LDP) CRISP - Cross Registry Internet Service Protocol (CRISP) CRL - Certificate Revocation List (CRL) *CRLF - Carriage-Return Line-Feed (ASCII control character sequence) CRMF - Certificate Request Message Format (CRMF) CRS - Coordinate Reference System (CRS) cRTP - compressed RTP (cRTP) CSIRT - Computer Security Incident Response Team (CSIRT) CSMA/CD - Carrier Sense Multiple Access with Collision Detection (CSMA/CD) CSNP - Complete Sequence Number PDU (CSNP) CSPF - Constrained Shortest Path First (CSPF) CSRC - contributing source (CSRC) CT_IU - Common Transport Information Unit (CT_IU) CTM - Cellular Text Telephone Modem (CTM) CTR - Counter Mode (CTR) CTS - clear to send (CTS) CUG - Closed User Group (CUG) CW - Control Word (CW) DA - Destination Address (DA) - Datamover Architecture (DA) (for iSCSI) DAC - Dynamic Authorization Client (DAC) DAD - Duplicate Address Detection (DAD) DARPA - Defense Advanced Research Projects Agency (DARPA) DASS2 - Digital Access Signaling System 2 (DASS2) DBA - Dynamic Bandwidth Allocation (DBA) DCCP - Datagram Congestion Control Protocol (DCCP) DCE - Data Communications Equipment (DCE) or - Distributed Computing Environment (DCE) DCOM - Distributed Component Object Model (DCOM) DCT - Discrete Cosine Transform (DCT) DD - Database Description (DD) DDDS - Dynamic Delegation Discovery System (DDDS) DDoS - Distributed Denial of Service (DDoS) DDP - Device Discovery Protocol (DDP) DDUL - Dynamic DNS Update Lease (DDUL) DE - Discard Eligible (DE) [flag in a Frame Relay frame] DELT - Dual Ended Loop Test (DELT) *DER - Distinguished Encoding Rules *DES - Data Encryption Standard (DES) DF - Don't Fragment (DF) DFZ - Default-Free Zone (DFZ) DGIWG - Defence Geospatial Information Working Group (DGIWG) DHAAD - Dynamic Home Agent Address Discovery (DHAAD) *DHCP - Dynamic Host Configuration Protocol (DHCP) *DHCPv6 - Dynamic Host Configuration Protocol for IPv6 (DHCPv6) DID - Direct Inward Dialing (DID) - see note in terms list. DIFS - Distributed Interframe Space (DIFS) DIT - Directory Information Tree (DIT) DKIM - DomainKeys Identified Mail (DKIM) DLCI - Data Link Connection Identifier (DLCI) DLSw - Data Link Switching (DLSw) [A forwarding mechanism for the IBM SNA (Systems Network Architecture). It places SNA NPDUs into a TCP connection between two routers, which tunnel them across an IP network.] DLV - DNSSEC Lookaside Validation (DLV) DN - Distinguished Name (DN) DNA - Detecting Network Attachment (DNA) *DNS - Domain Name System DNSSEC - DNS Security (DNSSEC) or - DNS Security Extensions (DNSSEC) DOCSIS - Data Over Cable Service Interface Specification (DOCSIS) DOI - Domain of Interpretation (DOI) DoS - Denial of Service (DoS) *DDoS - Distributed denial of service DPI - deep packet inspection (DPI) DPNSS - Digital Private Network Signaling System (DPNSS) DR - designated router (DR) DRB - Designated RBridge (DRB) DRBG - deterministic random-bit generator (DRBG) DRS - DGIWG Registry System (DRS) DRM - Digital Rights Management (DRM) DS - Diffserv (DS) - Differentiated Services (DS) - Delegation Signer (DS) DSA - Digital Signature Algorithm (DSA) DSACK - Duplicate Selective Acknowledgement (DSACK) DSAP - Destination Service Access Point (DSAP) DSCP - Differentiated Services Code Point (DSCP) DSDL - Document Schema Definition Languages (DSDL) DSE - DSA-Specific Entry (DSE) *DSL - Digital Subscriber Line (DSL) DSLAM - Digital Subscriber Link Access Multiplexer DSP - Digital Signal Processor (DSP) or - Digital Signal Processing (DSP) DSRK - Domain-Specific Root Key (DSRK) DSS - Digital Signature Standard (DSS) DSUSRK - Domain-Specific Usage-Specific Root Keys (DSUSRK) *DTD - Document Type Definition Deactivation Time Delay (DTD) DTE - Data Terminal Equipment (DTE) DTLS - Datagram Transport Layer Security (DTLS) DTMF - dual-tone multi-frequency (DTMF) DTN - Delay-Tolerant Networking (DTN) DTS - decoding time stamp (DTS) or - decode time stamp (DTS) DTX - Discontinuous Transmission (DTX) DUA - DASS 2 Extensions (DUA) DUID - DHCP Unique Identifier (DUID) DUNS - Data Universal Numbering System (DUNS) DUT - Device Under Test (DUT) DVB - Digital Video Broadcasting (DVB) DVI - No Expansion DVMRP - Distance Vector Multicast Routing Protocol (DVMRP) E.164 - No Expansion Refers to a telephone numbering plan as specified by the ITU-T E.164 specification E-LSP - Explicitly TC-encoded-PSC LSP (E-LSP) (note: expansion in RFC 3270 was updated by RFC 5462) EAP - Extensible Authentication Protocol (EAP) *EBCDIC - Extended Binary Coded Decimal Interchange Code (EBCDIC) eBGP - External Border Gateway Protocol (eBGP) EBM - Equipped Bit Mask (EBM) ECAM - European Committee for Academic Middleware (ECAM) EC2N - elliptic curve group over GF[2^N] (as in EC2N group) ECC - Elliptic Curve Cryptography (ECC) ECDH - Elliptic Curve Diffie-Hellman ECDSA - Elliptic Curve Digital Signature Algorithm (ECDSA) ECM - Error Correction Mode (ECM) ECMP - Equal Cost Multi-Path (ECMP) or - Electronic Commerce Messaging Protocol (ECMP) EC2N - Elliptic Curve Group over GF[2^N] (as in EC2N group) ECN - Explicit Congestion Notification (ECN) ECP - Elliptic Curve Group over GF[P] (as in ECP group) or - Electronic CodeBook (ECP) or - Encryption Control Protocol (ECP) ECT - ECN-Capable Transport (ECT) EDCA - Enhanced Distributed Channel Access (EDCA) EDGE - Enhanced Data rates for GSM Evolution (EDGE) EDI - Electronic Data Interchange (EDI) EDIINT - Electronic Data Interchange - Internet Integration (WG name) EF - Expedited Forwarding (as in "Diffserv EF") EFCI - Explicit Forward Congestion Indication (EFCI) EFM - Ethernet First Mile (EFM) EFR - Enhanced Full Rate (EFR) *EGP - Exterior Gateway Protocol *EHLO - Extended Hello For the template in RFC 5321, "EHLO" is specified a term of art, not an abbreviation. EID - Endpoint Identifier (EID) EIP - Extended Internet Protocol (EIP) EISS - Extended Internal Sublayer Service (EISS) ELOC - Endpoint Locator (ELOC) EMS - Energy Management Systems (EMS) (RFC 6272 - Smart Grid) EMSK - Extended Master Session Key (EMSK) ENUM - No Expansion Refers generally to a telephone numbering plan. However, the term ENUM is universal, whereas Telephone Number Mapping is not. There are ENUM activities and organizations all over the world. The "long name" of the ENUM WG long name is the anomaly, because ENUM is not an abbreviation, despite appearances. *EOF - End of File (EOF) EOF - Extended Options and Flags (EOF) *EOR - exclusive or [In logical operations, the exclusive disjunction, also called exclusive or, (symbolized XOR or EOR), is a type of logical disjunction on two operands that results in a value of "true" if and only if exactly one of the operands has a value of "true." (wikipedia)] EPI - Educational Policy Institute (EPI) EPON - Ethernet Passive Optical Network (EPON) EPP - Extensible Provisioning Protocol (EPP) EPS - Evolved Packet System (EPS) ERE - Extended Regular Expressions (ERE) ERO - Explicit Route Object (ERO) ES - Errored Seconds (ES) ESADI - End-Station Address Distribution Information (ESADI) ESB - Extension Security Block (ESB) ESI - Error Source Identifier (ESI) (RFC 5974) or - Entity Status Inquiry (RFC 4171) or - Encoding Symbol ID (RFC 5053) - Energy Services Interface (ESI) (RFC 6272 - Smart Grid) *ESMTP - Extended Simple Mail Transfer Protocol ESN - Electronic Serial Number (ESN) or - Extended Sequence Number ESO - Extended Security Option (ESO) ESP - Encapsulating Security Payload (ESP) ESS - Extended Service Set (ESS) ETS - Emergency Telecommunications Service (ETS) *ETSI - European Telecommunications Standards Institute (ETSI) EUI - Extended Unique Identifier (EUI) EVRC - Enhanced Variable Rate CODEC (EVRC) EWMA - exponentially weighted moving average (EWMA) FA - forwarding adjacency (FA) - Foreign Agent (FA) FAD - feature and attribute data (FAD) FAN ELS - Fabric Address Notification Extended Link Service (FAN ELS) Pronounced "fan ee el es". FARP - Fibre Channel Address Resolution Protocol (FARP) Pronounced "farp". FBL - Feedback Loop (FBL) FCAPS - Fault, Configuration, Accounting, Performance, and Security (FCAPS) FCI - Feedback Control Information (FCI) FCIP - Fibre Channel Over TCP/IP (FCIP) FCP - Fibre Channel Protocol (FCP) FCS - Frame Check Sequence (FCS) FDDI - Fiber Distributed Data Interface (FDDI) FE - Forwarding Element (FE) FEC - Forward Error Correction (FEC) or - Forwarding Equivalence Class (FEC) (MPLS; RFC 3031) FECN - Forward Explicit Congestion Notification (FECN) FF - Fixed-Filter (FF) ffs - for further study FFT - Fast Fourier Transform (FFT) FG - forest guide (FG) FI - Forwarding Indicator (FI) FIA - form interpretation algorithm (FIA) (W3C VoiceXML 2.0) FIB - Forwarding Information Base (FIB) *FIFO - First In, First Out [This is listed in Merriam Websters Dictionary.] FII - Forked Instance Identifier (FII) FIN - Not expanded TCP flag bit name; see SYN. FMIPv6 - Fast Handovers for Mobile IPv6 (FMIPv6) FMT - feedback message type (FMT) ForCES - Forwarding and Control Element Separation (ForCES) FPGA - Field Programmable Gate-Array (FPGA) FPS - Frames Per Second (FPS) FQDN - Fully Qualified Domain Name (FQDN) FR - Frame Relay (FR) FRR - Fast Reroute (FRR) FSM - Finite State Machine (FSM) FSPF - Fabric Shortest Path First (FSPF) FSSI - FEC-Scheme-Specific Information (FSSI) FT - feedback target (FT) *FTP - File Transfer Protocol FWS - folding white space (FWS) GAL - Generic Associated Channel Label (GAL) (RFC 5586) or G-ACh Label (GAL) (RFC 5586) GARP - Generic Attribute Registration Protocol (GARP) GAS - Generic Advertisement Service (GAS) GbE - Gigabit Ethernet (GbE) GCKS - Group Controller/Key Server (GCKS) GCM - Galois/Counter Mode (GCM) GCO - Global Concurrent Optimization (GCO) GDOI - Group Domain of Interpretation (GDOI) GGSN - Gateway GPRS Support Node (GGSN) GLB - Global Locator Block (GLO) GLOP - No Expansion GMAC - Galois Message Authentication Code (GMAC) GMII - Gigabit Media Independent Interface (GMII) GML - Geography Markup Language (GML) *GMPLS - Generalized Multi-Protocol Label Switching GMRP - GARP Multicast Registration Protocol (GMRP) GNSS - Global Navigation Satellite System GPL - General Public License (GPL) GPRS - General Packet Radio Service (GPRS) GRE - Generic Routing Encapsulation (GRE) GRUU - Globally Routable User Agent URI (GRUU) GSAKMP - Group Secure Association Key Management Protocol (GSAKMP) GSE - Generalized Structure Element (GSE) GSI - Grid Security Infrastructure (GSI) GSM - Global System for Mobile Communications (GSM) GSPD - Group Security Policy Database (GSPD) GSS-API - Generic Security Service Application Program Interface (GSS-API) GSTN - Global Switched Telephone Network (GSTN) GTK - Group Temporal Key (GTK) gTLD - Generic Top Level Domain (gTLD) GTP - Generic Tunneling Protocol (GTP) GTSM - Generalized TTL Security Mechanism (GTSM) *GUI - Graphical User Interface GUID - Globally Unique Identifier (GUID) GVRP - Generic VLAN Registration Protocol (GVRP) HA - Home Agent (HA) HBA - Host Bus Adapter (HBA) or - Host-Based Authentication (HBA) or - Hash-Based Addresses (HBA) (RFC 5535) HC - high capacity (HC) HDLC - High-Level Data Link Control (HDLC) HFC - Hybrid Fiber Coaxial (HFC) HG - home gateway (HG) HIP - Host Identity Protocol (HIP) hIPv4 - hierarchical IPv4 HIT - Host Identity Tag (HIT) HKDF - HMAC-based Key Derivation Function (HKDF) HLR - Home Location Register (HLR) HMAC - Hashed Message Authentication Code (HMAC) HMIPv6 - Hierarchical Mobile IPv6 (HMIPv6) HoA - Home Address (HoA) HSS - Home Subscriber Server (HSS) *HTTP - HyperText Transfer Protocol *HTML - HypterText Markup Language *IAB - Internet Architecture Board *IANA - Internet Assigned Numbers Authority IAX - Inter-Asterisk eXchange (IAX) IBGP - Internal BGP (IBGP) ICE - Interactive Connectivity Establishment (ICE) *ICMP - Internet Control Message Protocol ICRP - Incoming-Call-Reply (ICRP) ICRQ - Incoming-Call-Request (ICRQ) ICSA - International Computer Security Association (ICSA) ICV - Integrity Check Value (ICV) I-D - Internet-Draft (I-D) IDEA - International Data Encryption Algorithm (IDEA) IDNA - Internationalizing Domain Names in Applications (IDNA) IDRP - Inter-Domain Routing Protocol (IDRP) (ISO/IEC 10747) IDS - Intrusion Detection System (IDS) IE - Information Element (IE) *IEC - International Electronical Commission *IEEE - Institute of Electrical & Electronics Engineers *IESG - Internet Engineering Steering Group *IETF - Internet Engineering Task Force IF - intermediate frequency (IF) *iff - if and only if (from mathematical logic) IGD - Internet Gateway Device (IGD) *IGP - Interior Gateway Protocol (IGP) *IGMP - Internet Group Management Protocol IHL - Internet Header Length (IHL) IID - Interface Identifier (IID) IIH - IS-IS Hello (IIH) IKE - Internet Key Exchange Protocol (IKE) ILMI - Integrated Local Management Interface (ILMI) ILNP - Identifier Locator Network Protocol (ILNP) (RFC 5887) - Interim LNP (ILNP) ILV - Index-Length-Value (ILV) *IMAP - Internet Message Access Protocol IMPP - Instant Messaging and Presence Protocol (IMPP) IMS - IP Multimedia Subsystems (IMS) IMSI - International Mobile Subscriber Identity (IMSI) INCITS - INternational Committee for Information Technology Standards IOS - Internetwork Operating System (IOS); as in Cisco IOS *IP - Internet Protocol IPBX - IP Private Branch Exchange (IPBX) IPCP - IP Control Protocol (IPCP) IPFIX - IP Flow Information Export IPHC - IP Header Compression (IPHC) IPPM - IP Performance Metrics (IPPM) *IPsec - IP Security (IPsec) IPTV - No Expansion A service that delivers television signals over an RTP/UDP/IP video stream. It is read "IP TV". *IPv4 - Internet Protocol version 4 *IPv6 - Internet Protocol version 6 IPX - Internetwork Packet Exchange (IPX) IR - Initiation and Refresh (IR) IRI - Internationalized Resource Identifier (IRI) IS - Information Service (IS) or Intermediate System (IS) ISC - Internet Systems Consortium (ISC) ISID - Initiator Session Identifier (ISID) *IS-IS - Intermediate System to Intermediate System (routing protocol) ISAKMP - Internet Security Association and Key Management Protocol (ISAKMP) ISATAP - Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) iSCSI - Internet Small Computer System Interface (iSCSI) *ISDN - Integrated Services Digital Network (ISDN) *ISO - International Organization for Standardization *ISP - Internet Service Provider ISS - Internal Sublayer Service ISUP - ISDN User Part (ISUP) *ITU - International Telecommunication Union *ITU-T - ITU Telecommunication standardization sector IU - Information Unit (IU) IUA - ISDN Q.921-User Adaptations Layer (IUA) IV - Initialization Vector (IV) IVL - Independent VLAN Learning (IVL) IVR - Interactive Voice Response (IVR) IXFR - Incremental Zone Transfer (IXFR) KDC - Key Distribution Center (KDC) KDF - Key Derivation Function (KDF) KE - key establishment (KE) KEK - key encryption key (KEK) KEM - Key Encapsulation Mechanism KINK - Kerberized Internet Negotiation of Keys (KINK) KPML - Key Press Markup Language (KPML) L2F - Layer 2 Forwarding (L2F) L2TP - Layer 2 Tunneling Protocol (L2TP) L2VPN - Layer 2 Virtual Private Network (L2VPN) L3VPN - Layer 3 Virtual Private Network (L3VPN) L-LSP - Label-Only-Inferred-PSC LSP (L-LSP) *LACNIC - Latin American and the Caribbean Internet Addresses Registry LAG - Link Aggregation Group (LAG) *LAN - Local Area Network (LAN) LCAS - Link Capacity Adjustment Scheme (LCAS) LCCE - Logical Cluster Computing Environment (LCCE) or - L2TP Control Connection Endpoint LCI - Location Configuration Information (LCI) LCP - Location Configuration Protocol (RFC 5687) or - large content providers (LCP) (RFC 6306) - Link Control Protocol (LCP) ( LDAP - Lightweight Directory Access Protocol (LDAP) *LDP - Label Distribution Protocol (LDP) LER - Label Edge Router (LER) LFB - Logical Functional Block (LFB) - Logical Function Block (LFB) LFIB - Label Forwarding Information Base (LFIB) LFN - Long Fat Network (LFN) (RFC 2757) or - Local Fixed Node (LFN) (RFC 3963) LFSR - linear feedback shift register (LFSR) LIFO - last-in-first-out (LIFO) LIP - Loop Initialization Primitive Sequence (LIP) Pronounced "lip". LISP - Locator-Identifier Split Protocol (LISP) (RFC 5720) or Locator/ID Separation Protocol (LISP) (RFC 5887) LKH - Logical Key Hierarchy (LKH) LLC/SNAP - Logical Link Control/Subnetwork Access Protocol (LLC/SNAP) Pronounced "el el see snap". LLID - Logical Link Identifier (LLID) LLN - Low-Power and Lossy Network (plural LLNs) LLS - Link-Local Signaling (LLS) LMA - Local Mobility Anchor (LMA) LMDS - Local Multipoint Distribution Service (LMDS) LMP - Link Management Protocol (LMP) LOPS - Loss of Packet Synchronization (LOPS) LoST - Location-to-Service Translation (LoST) LRU - Least Recently Used (LRU) LSA - Link State Advertisement (LSA) LSAP - Link Service Access Point (LSAP) LSB - Least Significant Bit (LSB) LSC - Link State Control (LSC) - Lambda Switch Capable (LSC) LSDB - Link State Database (LSDB) LSE - Label Stack Entry (LSE) LSI - Local Scope Identifier (LSI) LSP - Label Switched Path (LSP) or Link State Packet (LSP) or Link State PDU (LSP) (or Link State Protocol Data Unit) LSR - Label Switching Router (LSR) - Loose Source Routing (LSR) (RFC 6301) LSRR - Loose Source and Record Route (LSRR) LSW - Least Significant Word (LSW) LTE - Long-Term Evolution (LTE) LUN - Logical Unit Number (LUN) LWSP - linear whitespace (LWSP) MA - Multicast Acquisition (MA) (RFC 6332) or - multiple attachment (MA) (RFC 6362) MA/RA - Maintenance Agency/Registration Authority (MA/RA) MAC - Message Authentication Code (MAC) or - Medium Access Control (MAC) or - Media Access Control (MAC) Caution when expanding these. Alfred provides the following info: a) IEEE 802.2 (et al.) : MAC == Media Access Control -- Sublayer of the Link Layer; most frequently used in combination with "address". I pose the rule of thumb: Whenever "MAC" appears in context with "address", it has to be expanded in the IEEE sense. b) Legacy cryptographic terminology : MAC == Message Authentication Code c) Media/Medium dependent upon plural/singular. Per Dan Romascanu for RFCs 5412-5418. MACE - Middleware Architecture Committee for Education (MACE) MAG - Mobile Access Gateway (MAG) *MAN - Metropolitan Area Network MANET - Mobile Ad Hoc Network (MANET) MAP - Mobility Anchor Point (MAP) MAS - Mobile Access Station (MAS) MC - Motion Compensation (MC) MCU - Multipoint Control Unit (MCU) MCMS - Multimedia Cable Network System (MCNS) MDA - Mail Delivery Agent (MDA) MDS - Maximal Separable Distance (MDS) *MD5 - Message Digest 5 (Typically not expanded) MED - Multi-Exit Discriminator (MED) MFIB - Multicast Forwarding Information Base (MFIB) MG - Media Gateway (MG) MGC - Media Gateway Controller (MGC) MGCP - Media Gateway Control Protocol (MGCP) MHAE - Mobile-Home Authentication Extension (MHAE) *MIB - Management Information Base MIC - Message Integrity Check (MIC) or - Message Integrity Code (MIC) MIDCOM - Middlebox Communications (midcom) MIDI - MIDI (Musical Instrument Digital Interface) Typically not expanded. If expand, make MIDI primary, that is, use "MIDI (Musical Instrument Digital Interface)", not "Musical Instrument Digital Interface (MIDI)". (per RFC Editor note for RFCs 4695 and 4696) MIKEY - Multimedia Internet KEYing (MIKEY) *MIME - Multipurpose Internet Mail Extensions MIN - Mobile Identification Number (MIN) MINE - Minimal Encapsulation in IP (MINE) MIP - Mobile IP MITM - man in the middle (MITM) [typically hyphenated as adj. before "attack"] MKI - Master Key Identifier (MKI) MLDv2 - Multicast Listener Discovery Version 2 (MLDv2) MLM - Mailing List Manager (MLM) MLPP - Multilevel Precedence and Preemption (MLPP) MMA - MIDI Manufacturers Association MME - Mobile Management Entity (MME) MMS - Multimedia Messaging Service (MMS) MN-FA - Mobile Node - Foreign Agent (MN-FA) MNG - Mobile Network Gateway (MNG) MOBIKE - IKEv2 Mobility and Multihoming (MOBIKE) MODP - modular exponentiation group (as in MODP group) MOS - mean opinion score (MOS) MOSPF - Multicast Extensions to OSPF (MOSPF) MP-BGP - Multiprotocol BGP MP2PE - Multi-Point to Point Emulation (MP2PE) *MPEG - Motion Picture Experts Group Typically not expanded. MPI - Minimum Picture Interval (MPI) *MPLS - Multiprotocol Label Switching Use "Multiprotocol" wherever "Multi Protocol" or "MultiProtocol" occur MPLS-TP - MPLS Transport Profile (MPLS-TP) MRD - Multicast Router Discovery (MRD) MRIB - Multicast Routing Information Base (MRIB) MRRU - Maximum Reconstructed Reception Unit (MRRU) MRT - Multi-threaded Routing Toolkit (MRT) MRTG - Multi Router Traffic Grapher (MRTG) MRU - Maximum Receive Unit (MRU) MS - Media Server (MS) MS-PW - Multi-Segment Pseudowire (MS-PW) MSA - Mail Submission Agent (MSA) - Message Submission Agent (MSA) - Mobility Service Authorizer (MSA) MSB - Most Significant Bits (MSB) MSCML - Media Server Control Markup Language (MSCML) MSDP - Multicast Source Discovery Protocol (MSDP) MSML - Media Server Markup Language (MSML) MSN - Master Sequence Number (MSN) MSRP - Message Session Relay Protocol (MSRP) MSS - Maximum Segment Size (MSS) or - Mobile Support Station (MSS) MSTP - Multiple Spanning Tree Protocol (MSTP) or Mobility Service Transport Protocol (MSTP) (RFC 5164) MSW - Most Significant Word (MSW) MTA - Mail Transport Agent (MTA) or - Mail Transfer Agent (MTA) *MTU - Maximum Transmission Unit MUA - Mail User Agent (MUA) or - Message User Agent (MUA) MVRP - Multiple VLAN Registration Protocol (MVRP) (IEEE 802.1ak) MWI - Message-Waiting Indicator (MWI) NAI - Network Access Identifier (NAI) NAL - Network Abstraction Layer (NAL) NAPT - Network Address Port Translation (NAPT) NAPTR - Naming Authority Pointer (NAPTR) NAR - New Access Router (NAR) NAS - Network Access Server (NAS) - Network-Attached Storage (NAS) (RFC 5532) *NAT - Network Address Translation (NAT) or - Network Address Translator (NAT) NAT-PMP - NAT Port Mapping Protocol (NAT-PMP) NAT-PT - Network Address Translation - Protocol Translation (NAT-PT) NAT-T - Network Address Translation Traversal (NAT-T) NBMA - Non-Broadcast Multi-Access (NBMA) NCP - Network Control Protocol (NCP) NCS - Network Control Signaling (NCS) ND - Neighbor Discovery (ND) NE - Network Element (NE) NEMO - Network Mobility (NEMO) NENA - National Emergency Number Association (NENA) NETCONF - Network Configuration Protocol (NETCONF) [Not typically expanded in titles, but expand in abstract] NEWPRED - No Expansion Refers to error resilience in MPEG-4 version 2 regarding which frame should be used as the reference for the next prediction. NFC - Normalization Form C (NFC) -- Unicode Normalization Form C NFS - Network File System (NFS) NIC - Network Interface card (NIC) Network Information Center (NIC) (as in AfriNIC, APNIC, LACNIC) NID - Network Interface device (NID) or - Network Identifier (NID) - Namespace Identifier (NID) NIDS - Network Intrusion Detection System NIS - Network Information Service (NIS) NIST - National Institute of Standards and Technology (NIST) NLM - Network Lock Manager (NLM) NLPID - Network Layer Protocol Identifier (NLPID) NLRI - Network Layer Reachability Information (NLRI) nMAG - new Mobility Access Gateway (nMAG) NMP - Network Musical Performance (NMP) NMS - Network Management System (NMS) NNI - Network-Network Interface (NNI) NNTP - Network News Transfer Protocol (NNTP) NORM - NACK-Oriented Reliable Multicast (NORM) NOS/OLS - Not_Operational Primitive Sequence / Offline Primitive Sequence (NOS/OLS) N-PE - Network-facing PE NREN - National Research and Education Network (NREN) NRPN - Non-Registered Parameter Numbers (NRPN) Note: the plural is used in MIDI documents NRZ - Non-Return-to-Zero (NRZ) NS - No Expansion as in "NS simulator" is network simulator, but should not be expanded NSAP - Network Service Access Protocol (NSAP) or Network Service Access Point (NSAP) NSCP - Name Server Control Protocol (NSCP) NSE - Named Signaling Event (NSE) NSEC - NextSECure (NSEC) *NSF - National Science Foundation NSIS - Next Steps in Signaling (NSIS) NSLP - NSIS Signaling Layer Protocol (NSLP) NSP - native service processing (NSP) or Network-Specific Prefix (NSP) NSS - Namespace Specific String (NSS) NSSA - Not-So-Stubby Area (NSSA) NTFS - New Technology File System (NTFS) *NTP - Network Time Protocol *NTSC - National Television Standards Committee NUD - Neighbor Unreachability Discovery NUT - Network Under Test (NUT) NVC - Number of Virtual Components (NVC) OA - Ordered Aggregate (OA) OAM - Operations, Administration, and Maintenance (OAM) per Adrian Farrell OASIS - Organization for the Advancement of Structured Information Standards (OASIS) O&M - OAM and Management (O&M) per Adrian Farrell OCR - optical character recognition (OCR) OCSP - Online Certificate Status Protocol (OCSP) ODU - Optical Data Unit (ODU) OFB - Output FeedBack (OFB) OFDM - Orthogonal Frequency Division Multiplexing (OFDM) OGC - Open Geospatial Consortium (OGC) *OID - Object Identifier OLSR - Optimized Link State Routing (OLSR) OLT - Optical Line Terminal (OLT) (Server unit of the EPON) OMA - Open Mobile Alliance (OMA) OMP - Optical Multi-Point (OMP) ONC - Open Network Computing (ONC) OPES - Open Pluggable Edge Services (OPES) ORCHID - Overlay Routable Cryptographic Hash Identifiers (ORCHID) *OSI - Open Systems Interconnection OSN - Original Sequence Number (OSN) *OSPF - Open Shortest Path First (routing protocol) OSSI - Open Source Software Institute (OSSI) OTAF - Over-the-Air Functionality (OTAF) OTASP - Over-the-Air Service Provisioning (OTASP) OTI - Object Transmission Information (OTI) OTN - Optical Transport Network (OTN) OTP - One Time Password (OTP) OU - Organizational Unit (OU) OUI - Organizationally Unique Identifier (OUI) OXC - Optical Cross-Connect (OXC) OWAMP - One-Way Active Measurement Protocol P2MP - Point-to-Multipoint (P2MP) P2P - peer-to-peer (P2P) or point-to-point (P2P) P2PE - Point-to-Point Emulation (P2PE) PA - provider-aggregated (PA) PAA - PANA Authentication Agent *PAC - Proxy Auto-Configuration (PAC) Not typically expanded; e.g., "the PAC file" or "Microsoft PAC" PAD - Peer Authorization Database (PAD) *PAL - Phase Alternation Line PANA - Protocol for Carrying Authentication for Network Access(5193) PAR - previous access router (PAR) PAT - Port Address Translation (PAT) PB - Provider Bridge (PB) (IEEE 802.1ad) PBA - Proxy Binding Acknowledgement (PBA) PBB - Provider Backbone Bridge (PBB) (IEEE 802.1ah) PBU - Proxy Binding Update (PBU) PBX - Private Branch Exchange (PBX) PCB - Payload Confidentiality Block (PCB) PCE - Path Computation Element (PCE) PCEP - Path Computation Element (PCE) Communication Protocol (PCEP) PCM - Pulse Code Modulation (PCM) *PCMU - Pulse Coded Modulation Pronounced 'mu-law' Not typically expanded PCP - Port Control Protocol (PCP) PCRF - Policy and Charging Rule Function (PCRF) *PDA - Personal Digital Assistant *PDC - Personal Digital Cellular (mobile phone standard) Similar to CDMA; should not be expanded. PDH - Plesiochronous Digital Hierarchy (PDH) PDN - Packet Data Network (PDN) PDP - Packet Data Protocol (PDP) PDS - Parameter Data Structure (PDS) PDSN - *PDU - Packet Data Unit or Protocol Data Unit PE - Provider Edge (PE) PEP - Policy Enforcement Point (PEP) PEM1 - No Expansion PEM-1 is not an abbreviation, it is an acronym, and cannot be expanded. PEN - Private Enterprise Number (PEN) PGP - Pretty Good Privacy (PGP) PHB - Per Hop Behavior (PHB) PHIB - Previous Hop Insertion Block (PHIB) PHOP - previous hop (PHOP) PHP - Penultimate Hop Popping (PHP) PHR - Per Hop Reservation (PHR) PHY - Physical Layer (PHY) PI - Provider Independent (PI) PIB - Payload Integrity Block (PIB) PIDF - Presence Information Data Format (PIDF) PIDF-LO - Presence Information Data Format Location Object (PIDF-LO) *PIM - Protocol Independent Multicast PIM-SM - Protocol Independent Multicast - Sparse Mode (PIM-SM) PKCS - Public-Key Cryptography Standards (PKCS) PKI - Public Key Infrastructure (PKI) PKINIT - Public Key Cryptography for Initial Authentication in Kerberos (PKINIT) *PKIX - Public Key Infrastructure using X.509 PL - Protocol Layer PLCP - Physical Layer Convergence Procedure (PLCP) PLR - Point of Local Repair (PLR) or - Packet Loss Rate (PLR) PLMN - Public Land-based Mobile Network (PLMN) PLPMTUD - Packetization Layer Path MTU Discovery pMAG - previous Mobility Access Gateway (pMAG) PMIPv6 - Proxy Mobile IPv6 PMTU - Path MTU (PMTU) PMTUD - Path MTU Discovery (PMTUD) PNNI - Private Network-Network Interface (PNNI) POI - Purge Originator Identification PON - Passive Optical Network (PON) POP - Point of Presence (POP) or - Post Office Protocol (POP) POSIX - Portable Operating System Interface (POSIX) POTS - Plain Old Telephone Service *PPP - Point to Point Protocol PPPoA - Point-to-Point Protocol over ATM (PPPoA) PPPoE - Point-to-Point Protocol over Ethernet (PPPoE) PPS - Packets Per Second (PPS) PPTP - Point to Point Tunneling Protocol (PPTP) PR-SCTP - Partially Reliable-Stream Control Transmission Protocol (PR-SCTP) PRF - Pseudorandom Function (PRF) PRL - Potential Router List (PRL) PRNG - Pseudorandom Number Generator (PRNG) PRR - Port-Range Router (PRR) (RFC 6346) or Policy Reserve Rule (PRR) (RFC 3989) PSAMP - Packet Sampling (PSAMP) PSAP - Public Safety Answering Point (PSAP) PSC - Packet Switch Capable (PSC) or PHB Scheduling Class (PSC) or Protection State Coordination (PSC) (RFC 5654) PSD - Power Spectral Density (PSD) *PSN - Public Switched Network or Packet Switched Network PSTN - Public Switched Telephone Network (PSTN) PT - payload type (PT) PTI - Payload Type Identifier (PTI) PTK - Pairwise Transient Key (PTK) PTM - Packet Transfer Mode (PTM) or Pulse-Time Modulation (PTM) PTS - presentation time stamp (PTS) PtM - Point to Multipoint (PtM) PtP - Point to Point (PtP) PVC - Permanent Virtual Circuit (PVC) PVP - Permanent Virtual Path (PVP) PW - pseudowire PWE3 - Pseudowire Emulation Edge-to-Edge (PWE3) QoE - Quality of Experience (QoE) QoP - Quality of Protection (QoP) QoS - Quality of Service (QoS) R2T - request-to-transmit (R2T) RA - Router Advertisement (RA) *RADIUS - Remote Authentication Dial-In User Service (RADIUS) Year 2006+ docs don't expand RADIUS in title RAID - Redundant Array of Independent Disks (RAID) RAMS - Rapid Acquisition of Multicast Sessions (RAMS) RAMS-R - RAMS Request (RAMS-R) RAMS-T - RAMS Termination (RAMS-T) RAN - Radio Access Network (RAN) RANGER - Routing and Addressing in Networks with Global Enterprise Recursion RAO - Router Alert Option (RAO) RAQMON - Real-time Application Quality-of-Service Monitoring (RAQMON) RBR - Realm Border Router (RBR) RCODE - No Expansion RD - Route Distinguisher (RD) RDDP - Remote Direct Data Placement Protocol (RDDP) RDF - Resource Description Framework (RDF) RDI - Remote Defect Indicator (RDI) - Remote Defect Indication (RDI) RDMA - Remote Direct Memory Access (RDMA) RDN - Relative Distinguished Name (RDN) RDS - Resolution Discovery System (RDS) REAP - Reachability Protocol (REAP) RED - Random Early Detection (RED) RF - radio frequency (RF) RFC - Request for Comments (RFC) RIB - Routing Information Base (RIB) RIID - Rendezvous Point Interface ID (RIID) *RIP - Routing Information Protocol *RIPE NCC - Reseaux IP Europeens Network Coordination Centre RIPng - Routing Information Protocol Next Generation (RIPng) RIR - Regional Internet Registry (RIR) RISC - Reduced Instruction Set Computer (or Computing) RJRS - Recovery Journal Receiver Structure (RJRS) RJSS - Recovery Journal Sending Structure (RJSS) *RLE - Run Length Encoding RLMI - Resource List Meta-Information (RLMI) RLOC - Routing Locator (RLOC) RLS - Resource List Server (RLS) RMON - remote (network) monitoring (RMON) ROHC - RObust Header Compression (ROHC) ROLL - Routing Over Low-Power and Lossy (ROLL) RP - Rendezvous Point (RP) RPC - remote procedure call (RPC) RPF - Reverse Path Forwarding (RPF) RPN - Registered Parameter Numbers (RPN) Note: the plural is used in MIDI documents RPSL - Routing Policy Specification Language (RPSL) RR - Resource Record (RR) or - receiver report (RR) or - Route Reflector (RR) (as used by BGP) RRO - Record Route Object (RRO) RRT - Return Routability Test (RRT) RS - Retransmission Server (RS) or - Router Solicitation (RS) *RSA - Rivest, Shamir and Adleman RSAES-OAEP - RSA Encryption Scheme - Optimal Asymmetric Encryption Padding (RSAES-OAEP) RSASSA-PSS - RSA Probabilistic Signature Scheme (RSASSA-PSS) RSSI - Received Signal Strength Indication (RSSI) RSTP - Rapid Spanning Tree Protocol (RSTP) RSVP - Resource Reservation Protocol (RSVP) RSVP-TE - RSVP - Traffic Engineering RTCP - RTP Control Protocol (RTCP) if RTP in RTCP needs to be expanded, should be expanded as: RTCP - Real-time Transport Control Protocol (RTCP) RTO - retransmission timeout (RTO) *RTP - Real-time Transport Protocol RTS - request to send (RTS) RTSP - Real Time Streaming Protocol (RTSP) RTT - round-trip time (RTT) RVS - Rendezvous Server (RVS) RZ - Return-to-Zero (RZ) S-NAPTR - Straightforward-Naming Authority Pointer (S-NAPTR) S-PE - Switching Provider Edge S2L - source-to-leaf (S2L) SA - security association (SA) or Source-Active (SA) or Source Address (SA) SACK - selective acknowledgment (SACK) SAD - Security Association Database (SAD) SAFI - Subsequent Address Family Identifier (SAFI) SAID - Security Association ID Historically (back to early drafts "SAId" is being used in MIB object Names, also in enumeration values like "Said" are being used; can leave them as is mainly because: a) NMS vendors and operators are familiar with that syntax for OBJECT names involving SAIDs b) It is risky to make global replace that could lead to SNMP syntax errors on deployment (e.g., global replace of SAId for SAID Fix in DESCRIPTION Clauses ONLY: "(SAID)" instead of "(SAId)" "SAID" instead of "SAId" SALT - Speech Application Language Tags (SALT) SAML - Security Assertions Markup Language (SAML) SAN - System Area Network (SAN) - Subject Alternative Name (SAN) SAOL - Structured Audio Orchestra Language (SAOL) SAP - Session Announcement Protocol (SAP) SAR - Segmentation and Reassembly (SAR) SASL - Simple Authentication and Security Layer (SASL) SAToP - Structure-Agnostic Time Division Multiplexing over Packet (SAToP) SAVI - Source Address Validation Improvement (SAVI) S-BGP - Secure Border Gateway Protocol (S-BGP) SBC - Session Border Controller (SBC) SBM - Subnet Bandwidth Manager (SBM) SBN - Source Block Number (SBN) SC - Softwire Concentrator (SC) SCCRP - Start-Control-Connection-Reply (SCCRP) SCCRQ - Start-Control-Connection-Request (SCCRQ) SCHAC - Schema for Academia (SCHAC) SCRAM - Salted Challenge Response Authentication Mechanism (SCRAM) SCSI - Small Computer System Interface (SCSI) SCTP - Stream Control Transmission Protocol (SCTP) SCVP - Simple Certificate Validation Protocol (SCVP) - Server-Based Certificate Validation Protocol (SCVP) S/D - Source/Destination (S/D) SDAT - Simple DNA address table (SDAT) SDES - source description (SDES) SDID - Signing Domain Identifier (SDID) SDH - Synchronous Digital Hierarchy (SDH) SDNV - Self-Delimiting Numeric Value (SDNV) SDO - Standards Development Organization (SDO) SDP - Session Description Protocol (SDP) SDU - service data unit (SDU) SECG - Standards for Efficient Cryptography Group (SECG) SEND - Secure Neighbor Discovery (SEND) SES - Severely Errored Seconds (SES) SFGMP - Source Filtering Group Management Protocol (SFGMP) SFMT - sub-feedback message type (SFMT) *SHA - Secure Hash Algorithm SHIM - Stanza Headers and Internet Metadata (SHIM) SI - softwire initiator (SI) SID - session ID or server ID or sender ID or Silence Insertion Descriptor (SID) (RFC 5459) or Silence Descriptor (SID) (RFC 5993) From Ingemar Johansson (author) There seelms to be two definitions: "Silence Descriptor" and "Silence Insertion Description". The 3GPP and ETSI definition seems to be "Silence Descriptor" SIFS - Short Interframe Space (SIFS) SIMD - single instruction, multiple data (SIMD) SIMPLE - SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE) *SIP - Session Initiation Protocol SIPP - Simple Internet Protocol plus (SIPP) SIPS - Session Initiation Protocol Secure (SIPS) SLA - Service Level Agreement (SLA) SLAAC - Stateless Address Autoconfiguration (SLAAC) SLI - Set-Link-Info (SLI) SLLA - Source Link-Layer Address (SLLA) SLLAO - Source Link-Layer Address Option (SLLAO) SLP - Service Location Protocol (SLP) SMDS - Switched Multimegabit Data Service (SMDS) SMF - Standard MIDI File (SMF) S/MIME - Secure/Multipurpose Internet Mail Extensions (S/MIME) SMIL - Synchronized Multimedia Integration Language (SMIL) SMIv2 - Structure of Management Information Version 2 (SMIv2) SMPTE - Society of Motion Picture and Television Engineers (SMPTE) *SMS - Short Message Service *SMTP - Simple Mail Transfer Protocol SMUX - SNMP Multiplex (SMUX) SN - Sequence Number (SN) Sn - No Expansion number value Sn in mathematical equations SNA - Systems Network Architecture (SNA) SNMP - Simple Network Management Protocol (SNMP) SNP - Subnetwork Point (SNP) or Sequence Number Packet (SNP) SNR - Signal-to-Noise Ratio (SNR) SNTP - Simple Network Time Protocol (SNTP) SOA - Start of Authority *SOAP - Simple Object Access Protocol But "a Web services messaging protocol; originally the acronym for Simple Object Access Protocol, the term is no longer defined in common use" -IEEE Computer Society "In previous versions of this specification the SOAP name was an acronym. This is no longer the case." - W3C (http://www.w3.org/TR/2007/REC-soap12-part1-20070427/) SOCKS - no expansion. name of protocol. SOHO - Small Office, Home Office (SOHO) SONET - Synchronous Optical Network (SONET) SPD - Security Policy Database (SPD) SPE - Synchronous Payload Envelope (SPE) SPF - Sender Policy Framework (SPF) Shortest Path First (SPF) 9/8/08 - SPF should be expanded in most if not all IS-IS documents as "Shortest Path First" rather than "Sender Policy Framework" SPI - Security Parameter Index (SPI) SPKM - Simple Public-Key GSS-API Mechanism (SPKM) SPME - Sub-Path Maintenance Element (SPME) SPNEGO - Simple and Protected GSS-API Negotiation SPVC - Switched Permanent Virtual Circuit (SPVC) *SQL - Structured Query Language SR - sender report (SR) SRLG - Shared Risk Link Group (SRLG) SRP - Secure Routing Protocol (SRP) - Secure Remote Password (SRP) SRR - status report request (SRR) SRTP - Secure Realtime Transport Protocol (SRTP) or Secure Real-time Transport Protocol (SRTP) (RFC 3711) SRTCP - Secure Realtime Transport Control Protocol (SRTCP) SRV - Service Record (SRV) SS-FSSI - Sender-Side FEC-Scheme-Specific Information (SS-FSSI) SS-PW - Single-Segment Pseudowire (SS-PW) SSAP - Source Service Access Point (SSAP) SSH - Secure SHell (SSH) Protocol SSID - Service Set Identifier (SSID) SSL/TLS - Secure Socket Layer/Transport Layer Security (SSL/TLS) SSM - source-specific multicast (SSM) SSP - scheme-specifc part (SSP) SSPI - Security Support Provider Interface (SSPI) SSRC - synchronization source (SSRC) SSRR - Strict Source and Record Route (SSRR) STP - Spanning Tree Protocol (STP) or Secure Transfer Protocol (STP) STS - Synchronous Transport Signal (STS) STUN - Session Traversal Utilities for NAT (STUN) - Simple Traversal of the UDP Protocol through NAT (STUN) (RFC 3489 -- obsolete) SUT - System Under Test (SUT) SVC - Switched Virtual Circuit (SVC) SVL - Shared VLAN Learning (SVL) SYN - No Expansion TCP flag bit name. See FIN. T-PE - Terminating Provider Edge (T-PE) TAMP - Trust Anchor Management Protocol TCAM - Ternary Content-Addressable Memory (TCAM) TCN - Topology Change Notification (TCN) *TCP - Transmission Control Protocol TDD - Telecommunication Device for the Deaf (TDD) TDM - Time Division Multiplexer (TDM) or - Time-Division Multiplexing (TDM) *TDMA - Time-Division Multiple Access See also CDMA TE - Traffic Engineering (TE) or - Traffic Engineered (TE) TED - Traffic Engineering Database (TED) TEI - Terminal Endpoint Identifier (TEI) TERENA - Trans-European Research and Education Networking Association (TERENA) TESLA - Timed Efficient Stream Loss-Tolerant Authentication (TESLA) TF-EMC2 - Task Force on European Middleware Coordination and Collaboration (TF-EMC2) TFRC - TCP Friendly Rate Control (TFRC) *TFTP - Trivial File Transfer Protocol TGS - Ticket-Granting Server (TGS) or - Ticket-Granting Service (TGS) TGT - Ticket-Granting Ticket (TGT) TIAS - Transport Independent Application Specific (Maximum) (TIAS) TIMIP - Terminal Independent Mobile IP (TIMIP) TKIP - Temporal Key Integrity Protocol (TKIP) TLD - Top-Level Domain (TLD) TLLA - Target Link-Layer Address (TLLA) TLS - Transport Layer Security (TLS) TLSP - TRILL Link State Protocol (TLSP) *TLV - Type-Length-Value (self-describing data) TML - Transport Mapping Layer TNCP - TRILL Network Control Protocol (TNCP) TNP - TRILL Network Protocol (TNP) ToIP - Real-time Text over Internet Protocol (ToIP) TOE - TCP Offload Engine (TOE) (RFC 5532) or - target of evaluation (TOE) (RFC 4949) TPGT - Target Portal Group Tag (TPGT) TPDU - Transport Protocol Data Unit (TPDU) TPM - Transport Performance Metrics (TPM) TRILL - Transparent Interconnection of Lots of Links (TRILL) TS - Traffic Selector (TS) TSN - Trunk Switched Network (TSN) or - Test Support Network (TSN) or - Transmission Sequence Number (TSN) (RFC 3708) TTD - Throughput Test Device (TTD) TTL - Time to Live (TTL) TU - Time Unit (TU) TUG - Tributary Unit Group (TUG) TURN - Traversal Using Relay NAT (TURN) (RFC 5245) or Traversal Using Relays around NAT (TURN) (RFC 5766) TV - Type/Value (TV) TWAMP - Two-Way Active Measurement Protocol (TWAMP) UA - User Agent (UA) UAC - User Agent Client (UAC) UAM - Universal Access Method (UAM) UAS - User Agent Server (UAS) - Unavailable Seconds (UAS) UDDI - Universal Description, Discovery, and Integration (UDDI) *UDP - User Datagram Protocol *UDP-Lite - User Datagram Protocol Lite UDPTL - UDP Transport Layer (UDPTL) UDVM - Universal Data/Voice Multiplexer (UDVM) UID - Unique Identifier (UID) ULA - Unique Local Addressing (ULA) (RFC 5887) - Unique Local Address (ULA) ULID - Upper-Layer Identifier (ULID) ULP - Unequal Loss Protection (ULP) UMA - Unlicensed Mobile Access (UMA) UMB - Ultra Mobile Broadband UML - Unified Modeling Language (UML) UMTS - Universal Mobile Telecommunications System (UMTS) UNI - User-Network Interface (UNI) U-NII - Unlicensed National Information Infrastructure (U-NII) UNSAF - UNilateral Self-Address Fixing (UNSAF) U-PE - User-facing PE UPnP - Universal Plug and Play (UPnP) *URI - Uniform Resource Identifier *URL - Uniform Resource Locator *URN - Uniform Resource Name uRPF - unicast reverse path forwarding (uRPF) *USB - Universal Serial Bus USRK - Usage Specific Root Keys (USRK) *UTC - Coordinated Universal Time *UTF-8 - Unicode transformation format 8. UTI - Universal Transport Interface (UTI) - note: Cisco UUID - Universally Unique Identifier (UUID) VACM - View-based Access Control Model (VACM) VAD - Voice Activity Detection (VAD) VBR-NRT - Variable Bit Rate - Non Real Time VBR-RT - Variable Bit Rate - Real Time VC - Virtual Circuit (VC) VCAT - Virtual Concatenation (VCAT) VCC - Virtual Channel Connection (VCC) VCCV - Virtual Circuit Connectivity Verification (VCCV) VCI - Virtual Channel Identifier (VCI) or - Virtual Circuit Identifier (VCI) VDL - Valid Data Length (VDL) VDSL - Very high bit-rate Digital Subscriber Line (VDSL) or - Very high speed Digital Subscriber Line (VDSL) VET - Virtual Enterprise Traversal (VET) *VLAN - Virtual Local Area Network VLB - Valiant Load-Balancing (VLB) VMR - Variable Multi Rate (VMR) VMR-WB - Variable Multi Rate WideBand (VMR-WB) VoIP - Voice over IP (VoIP) VPC - Virtual Path Connection (VPC) VPI - Virtual Path Identifier (VPI) VPIM - Voice Profile for Internet Mail (VPIM) *VPN - Virtual Private Network (VPN) VPLS - Virtual Private LAN Service (VPLS) VPWS - Virtual Private Wire Service (VPWS) VRF - VPN Routing and Forwarding (VRF) (RFC 4026) or - Virtual Routing and Forwarding (VRF) (RFC 4382) VRP - VLAN Registration Protocol (VRP) VRRP - Virtual Router Redundancy Protocol (VRRP) VSP - Voice Service Provider (VSP) VT - Virtual Tributary (VT) VXML - Voice XML (VXML) *WAN - Wide Area Networks W-CDMA - Wideband Code Division Multiple Access (W-CDMA) WDM - Wavelength Division Multiplexing (WDM) WebDAV - WWW Distributed Authoring and Versioning (WebDAV) or Web Distributed Authoring and Versioning (WebDAV) (RFC 4918. Per Cyrus Daboo.) WEP - Wired Equivalent Privacy (WEP) WF - Wildcard-Filter (WF) WFQ - Weighted Fair Queuing (WFQ) *WG - Working Group WHT - Walsh-Hadamard transform (WHT) WiMAX - Worldwide Interoperability for Microwave Access (WiMAX) WLAN - Wireless Local Area Network (WLAN) WM - Wireless Medium (WM) WRR - Weighted Round Robin (WRR) WSP - whitespace WWN - World Wide Name (WWN) WWNN - World Wide Node Name (WWNN) WWPN - World Wide Port Name (WWPN) XDR - External Data Representation protocol (XDR) XLAT - translator (XLAT) *XML - EXtensible Markup Language XMLDSIG - XML Digital Signatures (XMLDSIG) XMLSIG - XML-Signature Syntax and Processing (XMLSIG) XMPP - Extensible Messaging and Presence Protocol (XMPP) XNQ - eXtended Network Quality (XNQ) *XOR - exclusive or (see EOR above) XR - Extended Report (XR) XSD - XML Schema Definition (XSD) XUI - XCAP User Identifier (XUI)