Subject: [payload] #8: tx-mode: do we need this?

From: "payload issue tracker" <[email-masked]>
Date: Fri, 27 Dec 2013 22:40:05 -0000

#8: tx-mode:  do we need this?

 Section 4.4

    The transmission mode is indicated by the tx-mode media parameter
    (see section 7.1).  If tx-mode is equal to "SST", SST MUST be used.
    Otherwise (tx-mode is equal to "MST"), MST MUST be used.

 Section 7.1

       tx-mode:

          This parameter indicates whether the transmission mode is SST
          or MST.

          The value of tx-mode MUST be equal to either "MST" or "SST".
          When not present, the value of tx-mode is inferred to be equal
          to "SST".

          If the value is equal to "MST", MST MUST be in use.  Otherwise
          (the value is equal to "SST"), SST MUST be in use.

          The value of tx-mode MUST be equal to "MST" for all RTP
          sessions in an MST.

 [BA] Is the tx-mode parameter needed?  If we negotiate transport
 parameters in SDP (including potentially SSRCs, recv-appId and appId) and
 require the receiver to be able to handle either MST or SST (perhaps with
 some limits communicated), then the decision on whether to use MST or SST
 can be left to the sender.

 In such a situation, SDP need not include a "tx-mode" parameter, except
 perhaps as a preference that could be ignored, in which case the  "MUST"
 language would not make sense.

 Note that I'm still assuming that O/A could utilize RFC 5583 to describe
 dependencies in MST (and utilize other parameters to describe SST
 settings).

-- 
-------------------------------------+-------------------------------------
 Reporter:                           |      Owner:  draft-ietf-payload-
  [email-masked]          |  [email-masked]
     Type:  defect                   |     Status:  new
 Priority:  major                    |  Milestone:  milestone1
Component:  rtp-h265                 |    Version:  1.0
 Severity:  Active WG Document       |   Keywords:
-------------------------------------+-------------------------------------

Ticket URL: <http://trac.tools.ietf.org/wg/payload/trac/ticket/8>
payload <http://tools.ietf.org/payload/>