RFC 4585, "Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF)", July 2006

Errata ID: 2853
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Ali Begen
Date Reported: 2011-07-05
Verifier Name: Robert Sparks
Date Verified: 2011-08-05

Section 4.2 says:

OLD:
      rtcp-fb-param      = SP "app" [SP byte-string]
                         / SP token [SP byte-string]
                         / ; empty
NEW:
      rtcp-fb-param      = [ SP "app" [SP byte-string]
                         / SP token [SP byte-string] ]


OLD:
      rtcp-fb-ack-param  = SP "rpsi"
                         / SP "app" [SP byte-string]
                         / SP token [SP byte-string]
                         / ; empty
NEW:
      rtcp-fb-ack-param  = [ SP "rpsi"
                         / SP "app" [SP byte-string]
                         / SP token [SP byte-string] ]


OLD:
      rtcp-fb-nack-param = SP "pli"
                         / SP "sli"
                         / SP "rpsi"
                         / SP "app" [SP byte-string]
                         / SP token [SP byte-string]
                         / ; empty
NEW:
      rtcp-fb-nack-param = [ SP "pli"
                         / SP "sli"
                         / SP "rpsi"
                         / SP "app" [SP byte-string]
                         / SP token [SP byte-string] ]

Notes:

During the AUTH48 of RFC 6285, we discovered a bug with the ABNF syntax in RFC 4585. The original ABNF in Section 4.2 (as noted above) is incorrect ("/ ;empty" is not a valid ABNF - RFC 5234 does not allow empty alternates).

The NEW text intends to fix it. There are 3 places where the same change should be applied (changes are identical).

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