Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

We are looking to converge VOIP and Data traffic onto a single wire so that our client's VOIP phones pass data through to the users computer. We are specing out a new Sonicwall NSA appliance to handle routing functions and layer 2 switches to manage VLANS. Not a huge network, medium sized.

What should I know about converging the networks onto a single wire? Obviously I'll want to prioritize voice traffic, is this handled solely in the Sonicwall with QoS configurations or do the layer 2 switches need to be configured differently? Any other pitfalls I should be aware of, or any good resources for learning more?

share|improve this question

1 Answer 1

Honestly, don't bother with QoS for voice in a small LAN scenario. One of our offices runs about 100 workstations and VoIP phones, and so long as you don't oversubscribe massivley to the desktop, it just don't matter. Voice traffic is nothing in the grand scheme of things, at most 64 kb/s per port. We discovered that QoS for our voice traffic was mis-configured on the local LAN, and could not have been working. But nobody noticed, so we just removed it from the switch config.

Now, if you have an inter-office WAN or VPN link, you really need QoS. We have a 10 Mb/s link to a branch with only 25 users, and it absolutely requires QoS for voice traffic. Station-to-station calls are generally okay, but anything involving conferencing would be toast without QoS. Also, our pipe ran at basically 100% all day from tip-off of the first NCAA tournament games this year, and voice would not have worked at all between offices without QoS.

If you're doing video or Microsoft Lync web conferencinng or similar video-type stuff as part of your phone system, my advice does not neceassarily apply, and you may need QoS on the LAN.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.