Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

some extension cannot hear me and I cannot hear from some extension also


Dear

I am facing a problem since a month I have CUCM 8.6 (1sub-2pub) but since a month some extension cannot hear couple extensions and this is a new case ,before it was working normally.
I checked network but every thing is ok
This case I faced is with in not more than 10 extensions ( my whole system include 1500 extensions )

Pls help

Sent from Cisco Technical Support iPad App

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

some extension cannot hear me and I cannot hear from some extens

We had a similar issue a while back. Phones would just drop calls / one way audio, both externally and internally. We checked everything starting with routing (typical issue), VLAN diagnosis, switch firmware upgrades (as the calls would get dropped between people on the same IP subnet) as the CUCM was working fine with phones at other locations. Like with you, this just suddenly happened and only hard restarting the phone would make it work again. The problem began to spread over the course of time.

In the end, we downloaded the latest firmware for the phones, pushed it out to a couple of problem phones for testing, and then out for everybody and we have never had the problem again.

I would, besides other troubleshooting items, install the newest firmware upgrade and see how that gones. I guess you have checked already, but make sure the subnet(s) that the phones are using for your voice vlan have enough DHCP leases for all the endpoints.

4 REPLIES
Cisco Employee

some extension cannot hear me and I cannot hear from some extens

If you call the other end and press the ? button twice, do you actually see the counters going up??

Are phones in the same network??

Is this particular to a phone model???

Most of the time this is caused by routing issues.

HTH

java

if this helps, please rate

www.cisco.com/go/pdihelpdesk

HTH

java

if this helps, please rate

www.cisco.com/go/pdi
New Member

Re: some extension cannot hear me and I cannot hear from some ex

Hi JAIME

thanks for your reply .

the extensions on the same network and same cucm server and also same phone model 6921.

And there is an extensions around working normally.

But still no solution for this issue.

Pls help..

Thanks

Sent from Cisco Technical Support iPad App

New Member

some extension cannot hear me and I cannot hear from some extens

We had a similar issue a while back. Phones would just drop calls / one way audio, both externally and internally. We checked everything starting with routing (typical issue), VLAN diagnosis, switch firmware upgrades (as the calls would get dropped between people on the same IP subnet) as the CUCM was working fine with phones at other locations. Like with you, this just suddenly happened and only hard restarting the phone would make it work again. The problem began to spread over the course of time.

In the end, we downloaded the latest firmware for the phones, pushed it out to a couple of problem phones for testing, and then out for everybody and we have never had the problem again.

I would, besides other troubleshooting items, install the newest firmware upgrade and see how that gones. I guess you have checked already, but make sure the subnet(s) that the phones are using for your voice vlan have enough DHCP leases for all the endpoints.

New Member

Re: some extension cannot hear me and I cannot hear from some ex

Thanks FRANK

It was DHCP problem.

Thanks

Sent from Cisco Technical Support iPad App

239
Views
0
Helpful
4
Replies
CreatePlease login to create content