Hi, This text is just relevant to G.729.1 and not to other codecs, so if you want to add a reason for the SHOULD it should be based on RFC4749 implementations that would not send M=1. Maybe the text should say that if DTX is offered the sender must set the M bit according to RFC 3551. Roni -----Original Message----- From: Spencer Dawkins [mailto:spencer@xxxxxxxxxxxxxxxxx] Sent: Tuesday, September 23, 2008 12:45 PM To: aurelien.sollaud@xxxxxxxxxxxxxxxxxx Cc: fluffy@xxxxxxxxx; ietf@xxxxxxxx; gen-art@xxxxxxxx; ron.even.tlv@xxxxxxxxx; tom.taylor@xxxxxxxxxx Subject: Re: Late Last Call Gen-ART review of draft-ietf-avt-rfc4749-dtx-update-01 Hi, Aurelien, I think we're good on almost everything in your response. On the SHOULD/MUST below, it could very well be OK to have this as SHOULD, but we've been asking for some indication of reasons why SHOULDs might not be implemented - which could be as simple as "there is a lot of deployed code that didn't implement this, because it was a SHOULD in RFC 3551". If you leave this as SHOULD, you might want to say something about the effect on receivers, since conformant sender implementations aren't doing something that the spec assumed they would be doing. In this case, you're saying that the receiver can't look at the M-bit to identify the beginning of a talkspurt, right? If you get any other feedback about SHOULD/MUST here, please take that into account, of course... Thanks, Spencer ----- Original Message ----- From: <aurelien.sollaud@xxxxxxxxxxxxxxxxxx> To: <spencer@xxxxxxxxxxxxxxxxx> Cc: <fluffy@xxxxxxxxx>; <ietf@xxxxxxxx>; <gen-art@xxxxxxxx>; <ron.even.tlv@xxxxxxxxx>; <tom.taylor@xxxxxxxxxx> Sent: Tuesday, September 23, 2008 4:20 AM Subject: RE: Late Last Call Gen-ART review of draft-ietf-avt-rfc4749-dtx-update-01 Hi Thank you for the review. Below some answers. Aurelien > 3. RTP Header Usage > > If DTX is used, the first packet of a talkspurt, that is, the first > packet after a silence period during which packets have not been > transmitted contiguously, SHOULD be distinguished by setting the M > > Spencer (review): why not MUST here? > [AS] It is the wording from RFC 3551 (4.1). It could be a MUST, but I saw no reason to be stronger than the RTP spec. _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf