QoS on ProCurve 5372XL

[IT_7]

Hi there,

I've included a Visio file for the illustration of my question. There are a few important details that I should clear ouyt before we begin:

1) All of this QoS is because of implementation of VoIP.

2) We will be using softphones (software on the computers) as telephones, so it will not be possible to create a seperate VoiceVLAN.

3) The prioritasion of traffic will be done by port numbers.

4) Once you make a call, you query the telephone system only once, and then make a peer-to-peer connection directly to the phone you're dialing.

In the setup that's attached, what will be the most beneficial way to use Qos?
As I see it, I can choose between DSCP and 802.1p, but which one would be better?

I look forward to your answer. Thanks in advance.

Rasmus

[Stuart Teo]

Rasmus,

It looks like you're going to be needing 802.1p if prioritization is based on port number. DSCP/diffserv would mean that the layer 4 & higher protocol adds TOS info to the packets. Does your VoIP use some H.23x protocol?

[IT_7]

First of all, thanks for your answer!

I just found out that the softphone program uses DiffServ and sets the bits before leaving the pc.
That means I will be running DiffServ ToS instead.

So, shouldn't it be enough to enable DiffServ and configure the used bit pattern to priority 7? Will this work across the tagged link between the switches?

Thanks in advance,
Rasmus

[Stuart Teo · Accepted solution]

Ramus,

Yes, it would be enough to enable diffserv and set that to priority 7. Yes, it will work across tagged links. It's independent of VLAN tagging.

Regards,
Stuart