Re: [rtcweb] Some language on "prioritization"

"Jeremy Laurenson (jlaurens)" <jlaurens@cisco.com> Fri, 04 April 2014 11:56 UTC

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From: "Jeremy Laurenson (jlaurens)" <jlaurens@cisco.com>
To: Harald Alvestrand <harald@alvestrand.no>
Thread-Topic: [rtcweb] Some language on "prioritization"
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Date: Fri, 4 Apr 2014 11:55:50 +0000
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Subject: Re: [rtcweb] Some language on "prioritization"
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Do we really want the default (lazy coder) behavior to be highest priority in this case?

I assume the priority is browser-wide and so this could disrupt other app's streams?

J


On Apr 4, 2014, at 4:52 AM, "Harald Alvestrand" <harald@alvestrand.no<mailto:harald@alvestrand.no>> wrote:

I assume this is the scheduler envisioned in -ndata:



      SCTP_SS_PRIORITY:  Scheduling with different priorities is used.
         Streams having a higher priority will be scheduled first and
         when multiple streams have the same priority, the default
         scheduling should be used for them.  The priority can be
         assigned with the sctp_stream_value struct.  The higher the
         assigned value, the lower the priority, that is the default
         value 0 is the highest priority and therefore the default
         scheduling will be used if no priorities have been assigned.



This sounds like a "strict" scheduler, in that higher priority queues will starve out lower priority ones completely. I remember having the discussion at an IETF meeting about whether we wanted a "strict" scheduler or a "weighted round robin" scheduler for this, but I wouldn't trust my memory with what the conclusion was.

Was the conclusion that we should do "strict" scheduling? If so, it may be best to make that consistent across the board - I had written in a "weighted" scheduler for media into the prioritization text that I started this thread with, but I think there's value to consistency.

(Note: -ndata has SS_PRIORITY in one place and SS_PRIO / SS_PRIO_INTER in another place. Is there a subtlety here I'm not seeing?)



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