VoIP & QoS

[lobo66]

Question may be a bit broad but just a general opinion on what most of you if any are using for a QoS scheme with VoIP ..

Thx ...

 

[jneiberger]

If you are mixing voice traffic with other traffic then you really need to use Low Latency Queueing if your IOS supports it. You must be able to provide a priority queue for real-time traffic or you will likely run into problems with voice quality.

 

[ADB100]

There is an excellent Cisco Press book out at the moment that has filled in a lot of holes that were missing (IMO) in the Cisco QoS story. It is called 'End-to-End QoS Network Design: Quality of Service in LANs, WANs and VPNs' by Tim Szigeti & Christina Hattingh.

A lot of the information is filtering through to CCO but this book has it all in one place and offers good explanations as to why certain configurations and values are detailed.

Good luck

Andy

 

[ADB100]

One more thing...

The downside is it is specifically aimed at Cisco's VoIP/AVVID solutions - specifically CallManager - so the DSCP, IP Precedence and 802.1p CoS values represented are what Cisco use and not necessarily what other vendors use. There is very little mention of any other vendors equipment. It is easy enough to work around the text though and apply the logic to your own VoIP equipment.

Andy

 

[computerhighguy]

Have you determined if you really need QoS? For most SMB installations, a seperate VLAN is all that is really required unless you are using 802.11b phones. If so, the AP need a lot of work and it is best to set QoS on the switch port as well.


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