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Re: impact of bundle and retch-mux on the number of Transports

From: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
Date: Wed, 2 Dec 2015 06:50:49 +0000
To: Alexandre GOUAILLARD <agouaillard@gmail.com>, "<public-webrtc@w3.org>" <public-webrtc@w3.org>
Message-ID: <1447FA0C20ED5147A1AA0EF02890A64B373FCB6B@ESESSMB209.ericsson.se>
On 27/11/15 20:39, Alexandre GOUAILLARD wrote:
> Hi,
> I'm trying to draw what the pipeline would be in different cases, to
> make it easier to understand, and I'm stuck in a few cases.

Hi Alex, putting in my understanding below.

> Let's suppose I have only one audio track.
> 1. If I (want to) use rtcp-mux,
>    1.a will both the "transport" and "rtcpTransport" attributes of the
> Sender point to the same object?

According to the spec, rtcpTransport will be null if rtcp-mux is used.

>    1.b Will I have only one ice transport ?


>    1.c if the answer to 2.b is Yes, what is the value of the "component"
> attribute, RTP or RTCP?

I don't think that clear from the spec. Filed an Issue 

> Let's now suppose I have one audio and one video track.
> 2. if I (want to) use BUNDLE,
>    2.a Do I need two transceiver / senders ?

Yes, a sender only handles one track (and in this case you have one 
video and one audio track)

>    2.b Do all the senders.transport, respectively senders.rtcpTransport
> point to the same DTLS transport.

all senders.transport point at the same DTLS transport, and all 
senders.rtcpTransport point at another DTLS transport (assuming not 
using rtcp-mux)

>    2.c will that be a unique DtlsTransport if I also use rtcp-mux?


> Let's suppose I have only one audio track and one data channel.
> 3. If I create a transceiver, I will only have a sender and a receiver
> but no sctp transport.
>    3.a Must I create an additional sctp transport object?

I think that is automatically created when you add a dataChannel

>    3.b What happen if I want to bundle and rtcp-mux all, should I re-use
> the DTLS transport from the transceiver to have a unique one?

I think this happens automatically (and with the current API you don't 
really create the transports explicitly, they are created as an effect 
of adding tracks/datachannels to the PeerConnection and are readonly 

>    3.c in that last case, how many ICE transport do I have ? (1, 2, or 3?)


>    3.d as in 1.c, what will be the value of the "Component" for the ICE
> trasnport(s) in this case?

As said, I think we must clarify this.

> Thanks in advance.
> Alex.
> --
> Alex. Gouaillard, PhD, PhD, MBA
> ------------------------------------------------------------------------------------
> Principal Architect - Citrix, San Francisco
> President - CoSMo Software Consulting, Singapore
> ------------------------------------------------------------------------------------
> sg.linkedin.com/agouaillard <http://sg.linkedin.com/agouaillard>
>   *
Received on Wednesday, 2 December 2015 06:51:42 UTC

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