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Basic VOIP question

‎10-05-2011 03:46 AM

Hi folks. First of all, please excuse the basic nature of this question! We are a company experiencing VOIP issues on our network. QoS is enabled for VOIP traffic. However I'm wondering if the topology is different to others out there. My understanding is that QoS is set on the traffic going out of a switch. Looking at what happens afterwards, if loads of traffic from different sites arrives in one central node, the QoS is not configured to work at the incoming point of view so performance will be poor at this point. In that case the problem would be generic so I now wonder if the successful VOIP implementations out there have an entirely separate network used for VOIP? Or am I missing something?

Thanks in advance.

6 REPLIES 6
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Application Acceleration

Re: Basic VOIP question

‎10-05-2011 04:24 AM

Hi,

 

This is the forum for the WX (WAN Acceleration). Please let us know, if this is related with WX or any other Juniper product? If its not WX, i suggest you to post this question to the appropriate Juniper product forum.

 

Thanks,

Magesh S.

Juniper Networks

Advanced JTAC Engineer - WX/MFC

 

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Re: Basic VOIP question

‎10-05-2011 04:53 AM

Thanks Magesh,

the VOIP QoS is set on the Juniper Accelerators and this seems the only forum possibly related to such topics?

BRGds,

Paul

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Re: Basic VOIP question

‎10-05-2011 05:59 AM

 

Hi Paul,

 

Have you created an Application Definition for the VOIP traffic? Is it enabled for Compression?

 

Usually we recommend the VOIP traffic not to be compressed. If its enabled for Compression, please remove it from Compression.

 

In WXC, by default we do Outbound QoS and the Inbound QoS is not enabled.

 

Please let us know, what is the Interception method configured in the WXC, QoS mode and is bandwidth detection enabled or not ? The Passthrough traffic is also QoS'd based on the QoS mode configured.

 

If you are looking for a design implementation for VOIP with WXC, then please get in touch with your local Juniper Sales Engineer, who can really help you in suggesting the best suitable design.

 

I hope this clarifies.

 

Thanks,

Magesh S.

Juniper Networks

Advanced JTAC Engineer - WX/MFC

 

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Re: Basic VOIP question

‎10-05-2011 07:56 AM

Thanks Magesh.

To respond to your questions:

  • The VOIP traffic is not enabled for compression.
  • On all WXC  packet interception is turn-off.
  • Bandwidth detection is turned on.

So my questions are now:

(1) should interception be turned on?

(2) am I correct in my assertion that the congestion of inbound traffic, which is not subject to the QoS rules, can cause inherant issues?

(3) do comapnies generally have a separate VOIP network or work quite happily on their own WAN?

 

Thanks in advance,

 

Paul

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Re: Basic VOIP question

‎10-05-2011 08:11 AM

 

Hi Paul,

 

(1) should interception be turned on?

 

>>> Not needed. Currently the WXC's are in Inline mode.

 

(2) am I correct in my assertion that the congestion of inbound traffic, which is not subject to the QoS rules, can cause inherant issues?

 

 

>>>>>> What is the QoS mode you have configured on the WXC's.

 

Have you created an Application Definition for the VOIP traffic? If yes, i'm assuming that the Application Definition is removed from compression, (as you said VOIP traffic is not compressed)

 

Please confirm the QoS mode and the Application Definition.

 

(3) do comapnies generally have a separate VOIP network or work quite happily on their own WAN?

 

>>>>> I'm sorry i dont have an answer for this. May be a Sales/System Engineer can answer this question.

 

 

Thanks,

Magesh S.

Juniper Networks

Advanced JTAC Engineer - WX/MFC

 

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Re: Basic VOIP question

‎10-17-2011 05:11 AM

Hi!

 

I can just fill out with a little part of the question but I work a lot with VoIP related stuff.

 

Normally you run VoIP in the same network as the data traffic otherwise you dont get a multiservice network and there not so big point to migrate to VoIP, this is the most common solution I have seen. In some rare case I have seen a hard separation of voice but that was a result of bad/time saving engineeering(dont think just do it the safe way).

 

I have a theory that if you have a very bad network and bandwidht Detection enabled the back off function will affect your voice traffic badly, not the WC's fault but thats the result of the function.

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