Best way to configure QOS

[carl_townshend]

Hi all

We have an issue on a site where our Video conference equipment betwen 2 sites keeps cutting off. There is a 4Mbit MPLS conenction between the 2 sites.

The VC equipment was put in the priority queue and given 1.5Mbits, even though it connects at 768k, however we still experience drops and loss of connection.

Yesterday I can see that there is some traffic that constantly takes the link to 4Mbits max bandwidth, So I configured a policer for these 2 devices to police them to 2.5 Meg.

Am I right in doing this? If the link was constantly at 4 Bit, even with QOS enabled before, would it still haev negative impact on the traffic?

and should I be shapping the traffic or policing the traffic for the 2 servers ?

cheers

[smehrnia]

Hi Carl

it could have helped if you posted a sample of ur QoS config.

if your Video traffic is the priority for you and other traffic like DATA fall into best effort class, I think you should prioritize ur Video Bandwidth (to reserve it) and let the rest of ur traffic (default-class) use the remaining bandwidth, plus a fair-queue for those 2 servers. no need to police them.

plz Rate if it helped,

Soroush.

[handoko wiyanto]

hi Carl,

whats the codec that you used for the VC equipment? from this perhaps we can measure the normal bandwidth requirement for this application to run smoothly

have you talk to the MPLS service provider regarding their QoS config? because we need to check the QoS on hop per hop basis.

regards,

[vmiller]

Do you know for a fact that your mpls provider is honoring your markings? Sometimes they don't.

[carl_townshend]

Hi

The codec used is h263 I think, and it's using g711 for the voice. I don't think the provider honours them, as it's not part of the service.

[handoko wiyanto]

yes, h263 can run in 768k, g711 is only 64k

you said you have the other traffic that eats the bandwidth, do you have any monitoring tools implement that can shows what traffic is that?

and when you experiencing drops and loss of connection, did you manage to capture the show interface command?

regards,