GSM security testing: where the action is [LWN.net]

GSM security testing: where the action is

Posted Sep 27, 2010 22:10 UTC (Mon) by marcH (subscriber, #57642)
In reply to: GSM security testing: where the action is by Cyberax
Parent article: GSM security testing: where the action is

Scalability issues aside, IP QoS usually falls into a chicken and egg problem where each potential IP bottleneck postpones implementation of QoS until other bottlenecks do it first.

Yes designing a brand new network is a nice opportunity but... seeing is believing.

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GSM security testing: where the action is

Posted Sep 28, 2010 11:40 UTC (Tue) by Cyberax (✭ supporter ✭, #52523) [Link] (4 responses)

QoS on cell phone providers' networks is not hard to do. They'll probably just do it per-protocol.

On the wide Internet it's probably not going to make much difference, anyway. Voice traffic is fairly narrow-band, even high-quality codecs do not require more than 64Kbit.

GSM security testing: where the action is

Posted Sep 28, 2010 15:44 UTC (Tue) by marcH (subscriber, #57642) [Link]

> On the wide Internet it's probably not going to make much difference, anyway. Voice traffic is fairly narrow-band, even high-quality codecs do not require more than 64Kbit.

Narrow band does not grant immunity from occasional packet loss and high latencies. Only QoS helps in such cases.

GSM security testing: where the action is

Posted Sep 30, 2010 7:18 UTC (Thu) by Cato (guest, #7643) [Link] (2 responses)

Talking to a local expert in mobile technology, I get a lot of scepticism about QoS for mobile - although it's enabled in the 3GPP UMTS standards, nobody seems to have enabled this. The radio link is critical and very variable - however it may be that IP QoS gets turned on for the mobile backhaul link from base station up to the core network, as this is turning into something of a bottleneck. Making QoS work does require quite a big investment in policy server infrastructure, adapting your use of network planning tools, and so on, but this is probably paid back if you are using it to stop very large downloaders and ensure that VoIP and video are usable.

GSM security testing: where the action is

Posted Sep 30, 2010 13:03 UTC (Thu) by Cyberax (✭ supporter ✭, #52523) [Link] (1 responses)

Yeah, nobody uses QoS. It's not needed for data services (cell phone providers do not care if your Skype works badly if Youtube video is playing on your phone) and voice traffic goes over links with guaranteed bandwidth.

Quite often voice and data backbones also use separate circuits, so QoS is not used even there.

GSM security testing: where the action is

Posted Oct 6, 2010 9:39 UTC (Wed) by marcH (subscriber, #57642) [Link]

> and voice traffic goes over links with guaranteed bandwidth. Quite often voice and data backbones also use separate circuits, so QoS is not used even there.

This is actually some simple, manual, very coarse form of QoS when you think about it. Simple => works.