How to trouble shooting the problem of IPT?

[chinalumin]

There are 6 switches in LAN. All of them are cisco 3560. There are three vlans. Vlan 35 is for data vlan. Vlan 36 is for phone vlan. Vlan 38 is for CCM vlan. Recently, we found there are many packages lost between IP Phone in LAN. I monitored all interfaces in LAN. The bandwidth for all interfaces are normal. But the IP Phone, 7941, still lost many packages. I don't know how to resolve the problem. Can any one help me? Thanks!

[Kenneth Mohammed]

Where is the packet loss occurring? Between switch and phone, router and phone? Are you just trying to ping the phone from a router or switch? If so that is normal behavior for an IP phone. At least that has been my experience, that when you send an extended ping from switch/router to phone, you will experience some packet loss.

Hope that helped.

[chinalumin]

Thank you for your reply. My CCM version is 6.1. When I sent an extented ping. Every five or six packages, one package lost. Our vander said it is normal for 6.1 version. It's a protect mechanism in new version. So I have no way to detect whether it is the problem of switch network. All of the IP phone, 7941, are connected in LAN with six cisco 3560 switches. No router between each VLAN. When the problem occurs, the voice in the IP phone is like that in mobile phone.

On the IP Phone,7941, there is a item, settings->status->Call stat-> package lost. In this item, I can find the number is increasing.

[paolo bevilacqua]

Hi, it is normal that some ping packets are lost.

Where are you calling when you see packet loss on the phone display ?

[chinalumin]

There are more than 150 cisco 7941 IP Phones in our OA Lan. All of the IP Phones are connected in the same vlan in one office. I called from one IP phone to another in the same vlan. And the problem occurred.

[paolo bevilacqua]

Does it happen when you call between phones connected to the same switch ?

[chinalumin]

Yes, but not regular. Would you please provide your comments on this issue. And please advise how to set the mls qos on these switches in LAN. Thanks.