Re: [rmcat] Review of draft-ietf-rmcat-scream-cc-01

[Mirja Kühlewind <[e-mail]>]

Hi Karen, hi all,

see below.

On 14.07.2015 14:07, Karen Elisabeth Egede Nielsen wrote:
> HI,
>
>>> Other than that the mapping would be the
>>>> following way:
>>>>
>>>> NADA
>>>> ---
>>>> Reference Rate Calculator    -> Network congestion control
>>>> Video Target Rate Calculator -> Rate Control
>>>> Sending Rate Calculator      -> Transmission scheduler
>>>> Encoder                      -> Video Encoder
>>>> Rate Shaping Buffer          -> Queue RTP packets
>>>>
>>>> I think it would be super helpful to use a common terminology here
>>>> for everybody to better understand similarities and differences.
>>> [IJ] Agree, if we can come up with some common terms, so much the
>>> better
>>>
>> This (and the previous comment from Mirja and Ingemar on similarity
>> between NADA and SCReAM) tell that common terminologies should be used
>> in the different candidate drafts for ease of understanding if the terms
>> are
>> meaning the same things. We had a plan to have a framework document in
>> RMCAT. Will that help?
>>
> [Karen ] Yes I think that can be a good idea, but I am not sure that the
> above mapping of terms is right  - or is it  ?.
> I very likely can be mistaken, but with screams multiple stream view then I
> have thought that the following was the case:
>
> Scream Transmission scheduler is in fact a true transmission scheduler as it
> takes packets from the multiple RTP queues and schedule the packets
> (following whatever multiple-stream scheduling policy/stream priority
> relevant)
> for consummation of the global sending rate/the congestion window calculated
> and thus transmit the packets on the UDP socket (after which they eventually
> will
> go to the NIC for transmission). I further had assumed that pacing
> (vis-à-vis cwnv) in this design is implemented as part of the transmission
> scheduler and not as part of the RTP queue logic.
> This model at least corresponds to SCTP's model for scheduling of the
> multiple streams for consummation of CWND and transmission.

If I have red the current draft correctly, everything you've described here was 
moved to the appendix and all that is left in the main part is the calculation 
of the actual sending rate. In this case it would map (to NADA). Probably you 
want one image in the main part that is similar to the image in NADA and then 
have another image in the appendix where you show multiple sources and an 
actually transmission scheduler.

Mirja


>
> BR, Karen
>
>> --
>> Zahed
>>
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>> ANM ZAHEDUZZAMAN SARKER
>>
>>
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>> Services, Media and Network Features
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