Re: [rtcweb] additional ICE info

[Dan Wing <[e-mail]>]

On Sep 23, 2013, at 10:00 PM, Bernard Aboba <[e-mail]> wrote:

> Dan Wing said: 
> 
> "Another solution is MALICE which adds information to the ICE connectivity checks (bandwidth, drop preference, etc.) which can be DPI'd by network devices."
> 
> [BA]  I am fairly keen on adding some of this information to ICE, though not to assist DPI.   Rather, my concern is that with SDP being optional in WebRTC, some of the info that would otherwise be exchanged in the signaling channel may not be present, and if present, cannot necessarily be trusted, so that putting this into the ICE exchange has potential security value.  Also, in a situation where TURN servers are rented in the cloud, it can be useful to signal the maximum bandwidth that could be used for a given allocation.  

Yes, bandwidth is part of Microsoft's extensions to TURN as I'm sure you are aware (but others are probably not aware), http://msdn.microsoft.com/en-us/library/cc431507(v=office.12).aspx

The advantage of allowing routers along the path to see the bandwidth is they can influence their routing decisions to put the traffic on a better path (e.g., 3G versus microwave link versus satellite), prioritize the traffic, and do other things.  If the network always has sufficient bandwidth and thus no need to differentiate traffic, I agree there is no value and no purpose to tell the network anything.

> To my mind, the issue to be fixed in the TURN REST API wasn't necessarily the ability to steal credentials, but the ability to misuse those credentials in a way that could impose significant cost on the victim.  The act of mis-using a TURN credential does not by itself impose that cost -- but pumping huge amounts of traffic through it would. 

-d