cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
45373
Views
20
Helpful
10
Replies

Cisco IP Phones goes into Preservation Mode.

mangesh084
Level 1
Level 1

Hello Experts,

 

 I am facing one issue. We have CUCM servers and IP Phones in same LAN but stills Cisco IP Phones gets unregistered for 30 to 45 seconds when phone in idle mode. And in ongoing calls, phone goes in preservation mode. This is happening with any random IP Phone.

CUCM Ver is 10.5.

 

Can someone help out here?

 

Thanks in advance.

1 Accepted Solution

Accepted Solutions

I would still ask you to check your network. Switches, routers, firewall if any on the path.
Check if their is a monitoring system on your network that does polling during the time when the phones un-register.

View solution in original post

10 Replies 10

R0g22
Cisco Employee
Cisco Employee
Check your switchports for any errors. If there is a pattern, look into the cabling.

Thanks Nipun,

 

But I don't see any errors on switchports and also desktops are connected to PC ports of IP Phones are working fine.

Most of the time IP phones works but users are facing this problem 4 5 times in day.

Get a SDL trace for a couple of timestamps. The trace should be starting at a time when phones are registered and end when they re-register.

Hi Nipun,

 

I have collected packet capture of Phone and I found some logs as follows.

 

<Enum name="ReasonForOutOfService">10</Enum>

&

<Enum name="ReasonForOutOfService">23</Enum>

 

code 10 ==The TCP connection to the Cisco Unified Communication Manager experienced a timeout error

Code 23 ==The device closed the TCP connection due to a restart command from the Cisco Unified CM

 

But can you tell me possibilities  of why CUCM experienced a timeout error?

 

Regards,

Mangesh

I would still ask you to check your network. Switches, routers, firewall if any on the path.
Check if their is a monitoring system on your network that does polling during the time when the phones un-register.

Hello Guys,

 

 

  We found the root cause of this issue. We observed that CPU utilization of Access layer switches was more than 97% which was causing disconnection between CUCM and IP phone.

 

Regards,

Mangesh

 

Why can't you check cucm server clusters mgcp or cvp servers with rtmt logs, always saying that switches, routers , link, firewall, I'm asking one question , getting preservation mode related to call preserve or phone preserv

so what was the issue and what is the solution?  I have this issue as well.  We haven't had any issues with our system or any end points for over 4 years, but this year we are replacing switches and have two different admins managing the system with different sets of knowledge and different ways of doing the same thing.  Looking for what the solution was to make it stop.

Butanding
Level 1
Level 1

I just encountered this today, when we moved a user to a new building.

The cause, was a conflict between PoE from the switch and the VoIP phone having an external power source.

The old switch was not PoE.

Unplugging the external power and relying on PoE resolved the issue.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: