Application Acceleration
Application Acceleration

VoIP traffic compression

11.24.09   |  
‎11-24-2009 05:39 AM

Does enybody know how effective WXC devices compress VoIP traffic?

I have more that 50% of such traffic in my network and i am concern about acceleration and compression effectiveness.

7 REPLIES
Application Acceleration

Re: VoIP traffic compression

11.24.09   |  
‎11-24-2009 08:02 AM

VoIP is already pre-compressed. The WXC will do some minimal header compression only. Acceleration and QoS are of course quite beneficial to the traffic.

Kevin Barker
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Application Acceleration

Re: VoIP traffic compression

11.24.09   |  
‎11-24-2009 11:10 PM

Ok. I see. So it depends on payload size. Thanks!

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Application Acceleration

Re: VoIP traffic compression

11.25.09   |  
‎11-25-2009 07:05 AM

We only do passthrough on voice traffic.  We don't want any added latency or jitter added.  We just set QoS and pass it through.  What audio codec are you using?  I don't imagine you will receive much benefit from compressing voice traffic, depending on what codec you are using.  If you're using G711, you'd probably be better off going to G729 instead of having the accelerators compress it.

Application Acceleration

Re: VoIP traffic compression

[ Edited ]
11.26.09   |  
‎11-26-2009 02:24 AM

VoIP media is generally (not always) UDP-based RTP. Thus, no TCP acceleration and no NSR for UDP VoIP, only memory-based compression/MSR.

If you go along this route, you may wish to tweak meta-packet assembly timer which may affect delay and jitter for VoIP.

Rgds

Alex

 

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Application Acceleration

Re: VoIP traffic compression

11.26.09   |  
‎11-26-2009 03:16 AM

We use G711, and i think it is a good idea to migrate to G729. And also to use compressed RTP (cRTP). All, that i have understood from the discussion, is that it is not a good idea to use WXC for VoIP compression. We will sort it out with cRTP and proper QoS tuning. Thank you for your advices!

Application Acceleration

Re: VoIP traffic compression

04.02.10   |  
‎04-02-2010 07:19 AM

 


mello wrote:

Does enybody know how effective WXC devices compress  Voip Calls traffic?  I have more that 50% of such traffic in my network and i am concern about acceleration and compression effectiveness.


Thanks for the post and solution as we were having similiar issues using Linksys WAG54GP2.  We found it was a bit more complex to configure with the QoS but works beautifully now with excellent trafic monitoring and report  visibility.

 

 

 

Application Acceleration

Re: VoIP traffic compression

04.02.10   |  
‎04-02-2010 07:33 AM

Glad that this post helped you to solve your problem.