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Paul James

CUCM 7940 7960 upgrade issues

Warning to all potential upgraders with 7940 or 7960 phones


We recently upgraded to Call Manager 12.5, all appeared ok but when a 7940 or 7960 rebooted it updated its firmware to SIP, an issue as all were set up as SCCP. Quickly 200+ of our 600+ phones were out of service.

We use extension mobility and SIP does not support this on CUCM 12.5, so reprogramming was not an option.


When monitored the phone reported it could not locate the SCCP load file so then upgraded to SIP.

It appears that on a CUCM v11 it just ignores this and kept its SCCP firmware. TFTP download confirmed the files were present.


Eventually it was discovered that if the phone has a number of services assigned to the phone it exceeds the 7940 & 7960 config file maximum size limit of 8k, we had about 7 subscribed services. 


The missing file error is misleading, remove a couple of subscribed services and all works. 

Marianne Orban

Thank you for sharing, your post saved us a lot of time.

We have recently upgraded our CUCM cluster from v 11.0 to 12.5 and encountered this exact issue.


Hi, can you please expand below? I have SIP phones and I can use extension mobility on our CUCM 12.5.

"We use extension mobility and SIP does not support this on CUCM 12.5, so reprogramming was not an option."

According to the Cisco documentation the call manager 12.5 does not support Extension Mobility for 7940/60 phones in SIP mode.

Do you have experience of those models working on a 12.5.


I have also noticed that the upgrade adds the cross cluster configuration to the Extension Mobility Phone Services - &EMCC=#EMCC#

The old phones do not like this.

had the same issue

in my case there were a few 3rd party phone enterpirse services.

i removed them and bounced the phones and everything came back to normal


I opened a TAC case on a few of my 7940s changing gender. None of the ones that swapped are subscribed to anything so it must be something else. The ones that changed from SCCP to SIP were all ones that lost power or were unplugged to move to another location. I have a procedure to force them back which seems to work. Doesn't require a master reset or power cycle.


Did TAC give you a method to revert or is this something else that you came up with. Did you change the type in UCM by migrating them to SIP?

Here's how I "force" the phones back to SCCP. Your mileage may vary.

NOTE: I have zero 79XX sets using SIP so I have no qualms about step one in this procedure:

1: Change the default firmware load for 7940/60 SIP to same file name as the 7940/60 SCCP listings

2: Go to Device, Phone and located the rejected device

3: Copy the MAC address of the rejected phone (highlight, Ctrl + C)

4: Change first three characters of MAC to 999, click save and apply config

5: Load the same device type as the rejected set. It is described as SIP Gender changer. Paste the copied MAC into the MAC Field. Click save and apply config.

(I have a 7940 and 7960 set configured as SIP devices with one phone number NPA-555-1212 assigned)

6: Wait for this new device to obtain an IP address. Do not proceed until you can verify the device load by clicking on the phone's IP address. Phone will still show rejected. (Can take up to five minutes)

5: Change first characters to 888 for the rejected SIP device and save it, apply config.

6: Go back to original rejected device and change MAC address from 999 back to correct address (000)

7: Phone will now re-register correctly (can take up to two minutes)

Awesome will give it a try.

Could you tell me a bit more about Step 5...Load the same device type as the rejected set. It is described as SIP Gender changer

This PROC worjed great. Thank you!

Thomas. If you are trying to flip a 7940 from SIP back to SCCP then you need to create a
SIP 7940. If you are trying to flip a 7960 then you'd create a dummy SIP 7960.
This way you simply copy the MAC address of the flaky phone to the same model
"SIP" device and let it try and register. Once the "dummy" has an IP just change the MACs
back on both the original set and the Dummy and the flaky phone should reregister.
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