RFC Errata
Found 1 record.
Status: Verified (1)
RFC 8684, "TCP Extensions for Multipath Operation with Multiple Addresses", March 2020
Source of RFC: mptcp (tsv)
Errata ID: 6609
Status: Verified
Type: Technical
Publication Format(s) : TEXT, PDF, HTML
Reported By: Krishna Khanal
Date Reported: 2021-06-14
Verifier Name: Martin Duke
Date Verified: 2024-01-19
Section B.3 says:
initiator listener
| |
| S 0(20) <MP_CAPABLE>, <TFO cookie> |
| --------------------------------------------------------> |
| |
| S. 0(0) ack 21 <MP_CAPABLE> |
| <-------------------------------------------------------- |
| |
| . 1(100) ack 21 <DSS ack=1 seq=1 ssn=1 dlen=100> |
| <-------------------------------------------------------- |
| |
| . 21(0) ack 1 <MP_CAPABLE> |
| --------------------------------------------------------> |
| |
| . 21(20) ack 101 <DSS ack=101 seq=1 ssn=1 dlen=20> |
| --------------------------------------------------------> |
| |
Figure 19: The Listener Supports TFO
It should say:
initiator listener
| |
| S 0(20) <MP_CAPABLE>, <TFO cookie> |
| --------------------------------------------------------> |
| |
| S. 0(0) ack 21 <MP_CAPABLE> |
| <-------------------------------------------------------- |
| |
| . 1(100) ack 21 <DSS seq=1 ssn=1 dlen=100, M=1, A=0> |
| <-------------------------------------------------------- |
| |
| . 21(0) ack 1 <MP_CAPABLE> |
| --------------------------------------------------------> |
| |
| . 21(20) ack 101 <DSS ack=101 seq=1 ssn=1 dlen=20> |
| --------------------------------------------------------> |
| |
Figure 19: The Listener Supports TFO
Notes:
The example for TCP Fastopen with MPTCPv1 in RFC8684, Appendix-B.3 shows the listener sending an incorrect data-ack in its first data packet to the initiator sent immediately after its SYN-ACK.
At this point, the listener has not received the initiator's key, so it cannot generate the data-ack in it's response packets.
The correct behaviour would be to set flag 'A' to 0 and exclude sending data-ack until the initiator's key is received.