Phone 7821 and 8945 become unknown when restart the CUCM

[mohammad saeed]

Hi Guys,

I have around 600 IP phones (7821 + 8945) when I restarted the CUCM most of them became as Unknown devices and I have to make hard rest to return them back register in CUCUM?

What is the problem here?

Thanks,

MKS

[Georgios Fotiadis]

Do you have a clustered deployment or single node?

[mohammad saeed]

I have CUCM Pub+Sub

[Georgios Fotiadis]

Do both run the CallManager service, i.e. do you have phones register in both? If you reboot one CUCM, do they register to the other? How you perform the reboot?

[mohammad saeed]

yes both CUCM run CallManager Service. Actually not all phones but around the quarter of them became unknown devices that happened whe both cucm restarted?

[mohammad saeed]

the Status is None not unknown sorry!

[Georgios Fotiadis]

Which server do they register to normally? If you reboot that server, do they register to the other?

How exactly does your problem appear? You reboot both at the same time?

[mohammad saeed]

yes reboot both at the same time!

[mohammad saeed]

normally register with CUCM PUB and if PUB down will register with CUCM SUB. Yes If I rebooted the PUB will register with SUB but some phones will lose the connection with CUCM and status will be None

When Both servers down and after while both server comes up I lost a lot of 7821 + 8945 IP phones the registration with CUCM.

I saw the IP phones has the IP address from core sw DHCP but when I restart the IP phones the phone will not take the IP address until make hard reset for the phone the IP phone will take a new IP address and start registering with CUCM.

[mohammad saeed]

After long investigation the staff in the project said to me that the Electrical power turned off in All Edge switches and Data center.

I noticed it's a DHCP issue not from CUCM! after I restarted the ports of Phones in edge switches it started to register with CUCM!

but my question why DHCP not working properly? and Why some phones cannot registered with CUCM and they have IP address