Reviewer: Shuping Peng Review result: Ready with Issues Reviewer: Shuping Peng Review Result: Ready with Issues I am the assigned ART-ART reviewer for this draft (draft-ietf-rmcat-rtp-cc-feedback-10). Summary: I have some minor concerns about this document that I think should be resolved before publication. Major Issues: "No major issues found." Minor Issues: Abstract: "This memo discusses the types of congestion control feedback that it is possible to send using the RTP Control Protocol (RTCP), and their suitability of use in implementing congestion control for unicast multimedia applications." It is not clear what are the types of congestion control feedback considered in this draft. In Section 2, the "RTCP reception quality feedback" is mentioned but only once, while in the rest of this draft, "RTCP congestion control feedback" is considered [8888]. It seems that the "RTCP reception quality feedback" is directly taken as the "RTCP congestion control feedback". A proposal for the abstract of this draft, just for the author's reference: "This memo discusses the types of RTCP feedback that it is possible to send for the congestion control purposes, and their suitability of use in implementing congestion control for unicast multimedia applications." It would be better to provide a reference for "RTCP reception quality feedback", e.g. [RFC7201]? Section 2: "The RTP standards have long said that a 5% overhead for RTCP traffic is generally acceptable, while providing the ability to change this fraction. Is this still the case for congestion control feedback? " Is the congestion control feedback part of the overhead for RTCP traffic? If yes, then this sentence seems to be redundant. Or considering the context, maybe change it to something like, "The RTP standards have long said that a 5% overhead for RTCP traffic, including congestion feedback, is generally acceptable, while providing the ability to change this fraction." Section 3.1: Just wonder whether the descriptions regarding the classification of the RTCP feedback packets (i.e. full, compound, RTCP feedback packets, or reduced-size RTCP packets in the 3rd/4th/... paragraph) could be listed out at the beginning of the Section 3, since this information is referred in both following scenarios. Section 4: What are the "other media topologies"? It would be good to give some examples and references. Nits: * Section 2: s/The key question is how often does the receiver need to send feedback on the reception quality... of the network? /The key question is how often the receiver needs to send feedback on the reception quality ... of the network. s/Approaches like in-network filtering of acknowledgements have been proposed to reduce acknowledgement overheads ... can also /Approaches like in-network filtering of acknowledgements that have been proposed to reduce acknowledgement overheads ... can also s/it might make sense to give the option of sending congestion feedback less often than does TCP /it might make sense to give the option of sending congestion feedback less often than TCP does Section 3: s/comprise a 2 octet header/comprise a 2-octet header s/The RTCP congestion control feedback (CCFB) report comprises an 8 octet RTCP header and SSRC, a 4 octet report timestamp, and for each of the remote audio and video SSRCs, an 8 octet report header, and 2 octets per packet reported upon, and padding to a 4 octet boundary if needed /The RTCP congestion control feedback (CCFB) report comprises an 8-octet RTCP header and SSRC, a 4-octet report timestamp, and for each of the remote audio and video SSRCs, an 8-octet report header, and 2 octets per packet reported upon, and padding to a 4-octet boundary if needed s/How many RTP packets does the RTCP XR congestion control feedback packet included in these compound RTCP packets report on? /How many RTP packets does the RTCP XR congestion control feedback packet include in these compound RTCP packets report on? s/alternating compound and reduced-size reports gives results as shown in Table 4. /alternating compound and reduced-size reports give results as shown in Table 4. s/The use of reduced-size RTCP gives a noticeable reduction /The use of reduced-size RTCP reports gives a noticeable reduction * Section 4 s/close to it's current form/close to its current form -- last-call mailing list last-call@xxxxxxxx https://www.ietf.org/mailman/listinfo/last-call
