VoIP performance issue

[javed.mak]

Hello,

We are facing voice cutting or voice complete blank for seconds when IP phones are on one VLAN and ALU PABX on another VLAN. Everything is fine when IP phones and PABX on same VLAN.

Any idea?

Regards,
Ali

[cedric1]

Hello

Version of switch ?
Did you have packet loss ?
Some Ping trace ?

In my customer complete routing no issue on 9700/9800 V 6.3.1

Did you use mobility or fixed vlan ?

Cedric

[ar4uall]

Hi,
I had an issue similar to the one u r having at a customer site, also a 9000.
Tried different firmware versions, problem still persisted.
It would happen with any king of packet going across VLAN's , packet loss, slow response etc.
Problem is solved now. The problem was spanning tree.
We have 6850, 7800, 7700 and even older models no problem.
We installed 2 stacks of 6224 and we started to have problems.
The 6224 were trying to be the root bridge for the VLAN.
We just lowered the bridge priority value per VLAN on the 9000 to force it to be the root for every VLAN and that solved the problem.

Hope that helps.

[cedric1]

hello

This is the first thing to do if you install a network. Configure Root STP and backup Root STP on your TOP STP Switch.

Did you configure a backup STP Switch too ?

Nice that you have solve this issue

Cedric

[herege]

I'm experience the same problem of packet loss, but we use flat spanning tree.

Wich command did you issue in the 9000 to make it STP root per vlan?

Best regards,

[benny]

If you use flat-spanning-tree you only need to set a low bridge priority (while low means that smaller numbers have a higher priority).
If you want to use 1x1 STP (per-vlan-stp) you first need to make sure that other devices support this operation as well. (Understand what you do before you change the configuration.)