Subject: [AVTCORE] draft-ietf-avtcore-mprtp-03: Multipath RTP (MPRTP)

From: "Wang, Min" <[email-masked]>
Date: Thu, 22 Sep 2016 03:46:56 +0000

Hello AVT, Varun,

I need some help to understand the various SSRC fields in MPRTCP in Figure 12 in draft-ietf-avtcore-mprtp-03, copy and paste here. Assume two RTP streams with SSRC_A and SSRC_B are streamed from Host A to Host B. Host A has two interfaces (paths), A1 and A2. Each RTP stream is split into two subflows to be sent, one over interface A1, and the other over interface A2. To form the Subflow Sender Report of path A1, questions are

1.       What is "SSRC of packet sender" in line #2 below? SSRC_A or SSRC_B or "either one is ok"?

2.       What is "SSRC_1 (SSRC of first source)" in line #3 below? Assume the subflow of RTP stream with SSRC_A is listed first, then should SSRC_1  be SSRC_A?

3.       What is "SSRC of sender" in line #6 below? Should it be SSRC_A?

4.       To include the sender report of the subflow of the RTP stream with SSRC_B, right after line #11, SSRC_2 (=SSRC_B) and another 8 lines similar to line #4 to line #11 below are included. Is this understanding correct?

Thanks,
Min