Solved: CUCM 4.3 Change Hostname to IP

kevin.hu · ‎02-09-2012

Hi,

I just set up new 7962 and 7942 phones and registered to the CM 4.3. However, the phone loses soft buttons and line information pretty frequently and the entire LCD screen is just blank. After it goes blank, it takes awhile to have a "Configuring CM List" message. Unpluged the phone and reconnect the phone seems to solve the problem but the cycle starts again after a few minutes. I don't have the same problem with the older 7940 phones.

1. Why does the new phone lose its configuration while the old phone does not?

2. The CM 4.3 is configured with a hostname and DNS server cannot resolve it. If I change the hostname to an IP under System>Sever, will I have any negative impact on the CM 4.3?

3. How do I troubleshoot why the phone loses its configuration?

Thanks!

gstarr · ‎02-09-2012

Hi Kevin, I have never been a fan of using a hostname on Call Manager as I don't want the operation of my telephone system to be dependent on my DNS infrastructure. Just one more thing to keep my phones from working. You can change the hostname to an IP address without too much trouble, but please remember to change all of the URL entries in Enterprise parameters to IP addresses as well. This could also help your phones since all of the directory screens etc would now be relying on DNS to find the service URLs on your Call Manager.

As far as troubleshooting goes, you can look in the Call Manager logs. Sorry, but I don't remember exactly where they are on 4.3. You could also sniff the traffic on the phoe's switch port. BTW, you didn't mention whether you are using a cluster (PUB+SUB) or not and whether they cluster is split between multiple locations.

Thanks, Gene Starr, CCIE #8313

Please rate if useful.

View solution in original post

gstarr · ‎02-09-2012

It has been quite a while since I had to troubleshoot a Call Manager on Windows so I don't remember off the top of my head.

This link provides info on event log entries:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080111ac2.shtml

The other traces that will give you the most information are the CCM (also called SDI for Systems Diagnostics Interface) First you will need to enable them to the level that you want through Call Manager Serviceability > Trace > Configuration, then you can collect the traces through Trace > Collection. There's a lot more that I can't give you here. A book I frequently use is from Cisco Press called Troubleshooting Cisco IP Telephony. You will need to make sure that the book covers your version of Call Manager.

View solution in original post

gstarr · ‎02-09-2012

Hi Kevin, I have never been a fan of using a hostname on Call Manager as I don't want the operation of my telephone system to be dependent on my DNS infrastructure. Just one more thing to keep my phones from working. You can change the hostname to an IP address without too much trouble, but please remember to change all of the URL entries in Enterprise parameters to IP addresses as well. This could also help your phones since all of the directory screens etc would now be relying on DNS to find the service URLs on your Call Manager.

As far as troubleshooting goes, you can look in the Call Manager logs. Sorry, but I don't remember exactly where they are on 4.3. You could also sniff the traffic on the phoe's switch port. BTW, you didn't mention whether you are using a cluster (PUB+SUB) or not and whether they cluster is split between multiple locations.

Thanks, Gene Starr, CCIE #8313

Please rate if useful.

kevin.hu · ‎02-09-2012

Thanks Gene. Hostname was configured originally by another party and I am trying to reverse that. I just want to make sure it won't corrupt the CM database or some other serious repercussion. Thanks for the confirmation.

I only have one PUB that supports 100 phones. Where can I find these Call Manager logs?

gstarr · ‎02-09-2012

It has been quite a while since I had to troubleshoot a Call Manager on Windows so I don't remember off the top of my head.

This link provides info on event log entries:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080111ac2.shtml

The other traces that will give you the most information are the CCM (also called SDI for Systems Diagnostics Interface) First you will need to enable them to the level that you want through Call Manager Serviceability > Trace > Configuration, then you can collect the traces through Trace > Collection. There's a lot more that I can't give you here. A book I frequently use is from Cisco Press called Troubleshooting Cisco IP Telephony. You will need to make sure that the book covers your version of Call Manager.