Re: [MMUSIC] I-D Action: draft-ietf-mmusic-msrp-usage-data-channel-10.txt - Comment on msrp-cema attribute

Jose M Recio <> Thu, 25 April 2019 11:29 UTC

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To: Christer Holmberg <>, "" <>
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From: Jose M Recio <>
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Date: Thu, 25 Apr 2019 19:29:29 +0800
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Subject: Re: [MMUSIC] I-D Action: draft-ietf-mmusic-msrp-usage-data-channel-10.txt - Comment on msrp-cema attribute
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On 23/4/19 4:32 AM, Christer Holmberg wrote:

> Keep in mind (and that should probably better described in the document) that the normal MSRP routing procedures don't apply. The MSRP messages will be routed in the data channel, which is established between the SIP peers (or whatever signaling protocol is used). I guess proxies and application servers can look at the top-most path attribute, but that is not going to be the primary routing input. I don't think the draft says anything about that - it just seems to assume that the data channel will end up in the intended MSRP peer.

It indeed assumes that the data channel endpoint will be a MSRP peer, 
either another endpoint or a MSRP GW. If that's not clear enough it 
should be made more explicit.

If the endpoint is a GW, messages can be relayed, similar to the 
scenario where the connection to the GW is done using TLS, or 
WebSockets, instead of dc.