VLAN vs Diffserv for obtaining QoS

[mdfan]

Hi

Anyone having experience on these two methods to obtain
QoS of speech IP packages ?
In what kind of scenarios is VLAN to be preferred and oposite ?

Thanks !

 

[fidde]

VLAN do not actually give QOS but of course you can give one VLAN prioroty over the other. So in practic you get QOS but the big advantage with a VLAN is that if you have a big net (200 PC) you will get a lot of brodcast. If you put the phones on a seperat VLAN you can seperate this. with Ericsson's new phone 4425 you can configure the VLAN in the phone so that minimize the administration. But beware that there is a BUG in the phone so the PC connected to the phone will be taged with the same ID but new software is on it's way.

Conclusion:
Yes I think VLAN is a good thing for IP-phones. But there is just as much work to do in the IP infrastructure.

Fredrik