Packet Losses after Cisco IP Phones deployment

razam

Hi all,

We have implemented Cisco IP Telephony recently and are facing packet loss issues after deploying Cisco IP Phones.

Physical connection details

Access Switch ---> IP Phone ----> Computer.

IP Phone is connected directly to the switch and computer is connected to the IP Phone.

Obviously a separate voice and data vlan, different subnetworks for voice and data.

Now if we ping from computer to the default gateway (which is configured on the core switch), sometimes we see many packet losses, sometimes no packet losses. Its not stable.

if we remove the cable from the IP Phone and connect it directly to the computer. (computer to switch direct connection) then no packet loss at all and the network is stable.

if somebody has experienced this kind of problem before please give some advise. what is the issue ?

networker050184

What kind of troubleshooting have you done for the packet loss? Are the packets hitting the gateway?

busines4u

I ran into the same thing. Are you by chance using Cisco 8841 phones?

Here is a link for reference. The issue I had was in regard to Energy Efficiency being enabled on the computer. Once I disabled via Device Manager the issue went away.

A easier fix to this problem is to update the firmware on your phones that addresses this bug.

https://supportforums.cisco.com/discussion/12371761/cp-8841-pass-through-network-settings-ongoing-connectivity-issues

Alex90

Do you have auto qos configured?

razam

@busines4u, yess we are using 8841 phones. thank you for sharing the link, this is exactly the same problem what i am facing. solution given in the link is to upgrade the image of the phones to 10.2(2)ES5. will do that tomorrow.

@ Alex90, i configured Auto QoS on the switch interface but that didn't solve the issue.

@ networker, when PC is directly connected to the switch it works absolutely fine, problem comes only after using the IP Phone.

busines4u

Let us know how it goes!