Re: [rtcweb] Usefulness of ICE-TCP (Was: Comments on draft-ietf-rtcweb-transports-01)

Paul Giralt <pgiralt@cisco.com> Wed, 13 November 2013 19:54 UTC

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From: Paul Giralt <pgiralt@cisco.com>
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Date: Wed, 13 Nov 2013 14:54:17 -0500
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To: Markus.Isomaki@nokia.com
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Subject: Re: [rtcweb] Usefulness of ICE-TCP (Was: Comments on draft-ietf-rtcweb-transports-01)
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On Nov 13, 2013, at 2:43 PM, <Markus.Isomaki@nokia.com>; <Markus.Isomaki@nokia.com>; wrote:

> Typically gateways and conf server endpoints would be reachable by TCP. The question is thus how often a  "normal" (browser or mobile app) endpoint would be in a network where UDP is blocked but direct outgoing TCP connections are allowed. In that case ICE-TCP would be optimal way for that endpoint to connect with a gateway/server endpoint. TURN over TCP would solve the same case but is less optimal.
> 
> So unless people have data that shows that "UDP blocked but direct TCP allowed" is in itself a very rare setup (this is a question, I don't know that either), I think ICE-TCP is definitely worthwhile for a WebRTC endpoint to support. 

This is actually a very common firewall configuration for enterprise customers. Outbound TCP is allowed but UDP is blocked (even if UDP is initiated from the inside). 

-Paul