CP-7945G firmware downgrade...

[myers.christopher]

Is it possible to downgrade the firmware on a CP-7945G VoIP phone from the latest 9.4 version back to a 9.2 version?

[Brandon Pierce]

Just put the firmware you want specific to that phone model in the load field in device defaults.  You can get that information from the CUCM OS administration under TFTP file management and just search for the 79xx series loads.

[myers.christopher]

I'm good with the process.  However, when the phone tries to download the files for the older version, it gets the older "term45.default" file, but then fails to download the rest of the files.  Then the phone is stuck in the "upgrade" cycle, rebooting, downloading "term45.default", then failing on the rest of the files.  It seems as though you can't go backwards with firmware.

[Brandon Pierce]

Hm...I've reverted many times in the past with no issues. 

[Rob Huffman]

Hi Christopher,

Just to add a note to the good tips from Brandon (+5 "B")

Here is a note that is likely causing the issues you are seeing. It relates to the 7945 hardware version;

Hardware Updates

The hardware updates improve the compatibility of internal phone components.

The following table lists the updated hardware versions that require this release.

Phone	Hardware Version
Cisco Unified IP Phone 7942G	15.0 and higher
Cisco Unified IP Phone 7962G	15.0 and higher
Cisco Unified IP Phone 7945G	13.0 and higher
Cisco Unified IP Phone 7965G	13.0 and higher
Cisco Unified IP Phone 7975G	12.0 and higher

Phones manufactured with these hardware versions must run Firmware  Release 9.3(1)SR1 or later. The phone firmware does not allow the phone  to be downgraded to releases earlier than Release 9.3(1)SR1.

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/7900_series/firmware/9_3_1SR1/release_notes/P790_BK_R4E1E768_00_rn-9_3_1_sr1-7900-series_chapter_00.html#P790_RF_ND56648A_00

Cheers!

Rob

[recep.sefer]

I have the sama problem.

How can I learm my phones HW version

THANKS

[Rob Huffman]

Hi Recep,

The Version # (V13, V14, V15) should be on a sticker on the base of the phone under the footstand or you can web to the IP address of the phone.

Cheers!

Rob