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Keeping up data channel

From: <Markus.Isomaki@nokia.com>
Date: Mon, 11 Jun 2012 13:58:24 +0000
To: <public-webrtc@w3.org>
Message-ID: <E44893DD4E290745BB608EB23FDDB76223EA5F@008-AM1MPN1-041.mgdnok.nokia.com>
Hi,

In today's WebRTC meeting a discussion came up on how costly it is to keep an unused data channel connected. 

As long as we are using UDP, it is extremely costly for cellular connected mobile devices. In many networks keep-alives at least every 30 seconds are neeed to keep the UDP flow alive. And sending a packet wakes up a radio for some time. In worst case radio would be up all time, but even in a decent case quite high % of the overall cycle. That's quite different to e.g. normal websocket connection, where in the best case keep-alive period can be even more than 10 minutes. 

So, leaving data channels casually on, either by user or app, would be bad. At minimum some advice to app developers would be needed, but I'm afraind they might not pay attention to it. It's not clear to me what the options are, but it would be wise to close the channel after some time of inactivity and bring it up again when it's needed, even if that would require some delay. Or, alternatively, have the long-lived channels over TCP via a relay/server.

Markus 
Received on Monday, 11 June 2012 21:41:18 UTC

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