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

I'm fairly new to network design and I was wondering if someone could help clarify a couple of things regarding traffic prioritisation on a LAN.

Some background: I'm designing a network that will have a number of PCs connected via Ethernet, a number of wireless access points, server(s) storing multimedia content and server(s) for file storage. Ideally certain users' traffic would have a higher priority than others and traffic to/from the media server would have a higher priority as well.

I was thinking of using DiffServ prioritisation to avoid having to reset the priority field at each switch and configuring switches to automatically prioritise traffic to/from the MAC addresses of priority users and to/from the IP address of the media server.

Is this an appropriate way to approach the problem. Would using separate VLANs and prioritising those be a better solution?

share|improve this question
Sounds like premature optimization to me. On a modern, Gigabit LAN, you're going to be hard-pressed to starve your switching fabric of bandwidth; there will be a bottleneck somewhere else that impedes you, if any. –  gravyface Feb 16 '12 at 3:22
My first question would be why you need to prioritize traffic at all? Is there a business, economic, or political need or mandate that's driving your intention to prioritize traffic? –  joeqwerty Feb 16 '12 at 3:22
You could probably just tell the users "Your traffic has been prioritized," and that would resolve whatever (political) issue you're having. They'd probably never know the difference. –  Joel E Salas Feb 16 '12 at 3:32
Have you, without a doubt, determined that you are already experiencing contention on one or more of the switch uplink ports in your network? That is the first step you need to do. If you're not experiencing contention, QoS is not going to do you any good. –  EEAA Feb 16 '12 at 3:42
That's where a well-implemented, centrally-managed wireless system comes into play. You're sunk if you have a bunch of standalone APs. You need a real management system (Cisco and Aruba are two of the large players in this market) and a high enough concentration of APs to support your users. –  EEAA Feb 16 '12 at 4:10
show 5 more comments

Your Answer


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

Browse other questions tagged or ask your own question.