08 April

SIP firmware upgrade path that works with version 9 software

I recently purchased a used Cisco 7970 phone and wanted to
convert it to use the SIP protocol. I did a factory reset and soon
discovered that one cannot upgrade from the factory state
to a recent firmware build without first loading an intermediate firmware.
The problem is that the firmware in the phone validates any new firmware upload before installing it, and it does it using built-in authentication keys. Somewhere along the line Cisco changed the authentication keys used to validate the firmware, and old firmware will refuse to validate new firmware. In between, however, there were a few firmware versions that included the keys for both old and new. SIP firmware versions of those dual-key firmwares, however, are not readily available.

The problem is that while both old and new SIP firmwares can be downloaded for free, the intermediate "bridge" builds and not available from Cisco for free and require a paid Cisco account and I didn't want to get one just for this experiment.

I found a workaround by going through a pair of free SCCP firmwares (i.e. non-SIP software). The following sequence of re-flashes can probably be optimized, but it was faster for me to just go ahead this way.

Upgrading my phone directly to firmware version 8.5 (cmterm 8-5-2SR1) or any newer version led to an "AUTH FAIL" error. Here's what does work:

(Click to expand)

  • Upgrade to SIP70.8-2-1S
  • This is an old firmware that works on a factory-clean phone. This might not be needed and almost any old firmware is sufficient, but is where I started.

  • SCCP 8.5.2
  • Then upgrade to an old SCCP (AKA skinney) protocol firmware version 8.5.2, available for free from Cisco: SCCP70.8-5-2S (filename cmterm-7970_7971-sccp.8-5-2.zip)

  • SCCP 8.5.3
  • Then upgrade to a SCCP (skinny) protocol firmware 8.5.3
    This is also available free from Cisco. The actual zip package is cmterm-7970_7971-sccp.8-5-3.zip The important point is that this firmware includes the authentication keys for new builds! The corresponding SIP firmware cannot be download for free, incidentally.

  • SIP 9.4
  • Finally, you can upgrade to the free SIP firmware 9-4-2SR1

    Look for it at https://software.cisco.com/download/release.html?mdfid=278436620&softwareid=282074288&release=9.4(2)SR1

    Note that if you need to do all this via a TFTP server. For each
    phase unzip the corresponding firmware package, modify the XMLDefault.cnf.xml
    to indicate the loads file to use, and then reboot the phone.

    By Gregory Dudek at | Read (3) or Leave a comment |    
    Re: Upgrading Cisco 7970 phones and avoid AUTH FAIL

    Hi, Cisco removed the sccp firmwares for 7970g. Do you still have it lying around somewhere? Would you be able to PM me it? My 7970G is running SIP and i need cmterm-7970_7971-sccp.8-5-2.zip to change to SCCP.


    [ You didn't leave a contact address. -gd ]

    Posted by: thohawk at September 06,2017 16:48
    Re: Upgrading Cisco 7970 phones and avoid AUTH FAIL

    We recently upgrade the call manger and I really need the 7970 8.5.2 firmware. Can you send it to me please? dave@DemonstratedTech.com

    [Sorry, due you have the proprietary nature of that software I can't send it to you. In addition, and I'm not sure if I even have a copy.]

    Posted by: Dave at November 07,2017 23:26
    Re: Upgrading Cisco 7970 phones and avoid AUTH FAIL

    Cisco have removed the download link to all the 7970 firmware, Could you send over a copy of 9-4-2 please?

    [ I appreciate your predicament, but cannot personally send firmware images since I would be violating Cisco copyrights (it's also true that I am not sure if I have them anymore). Sorry!

    On the other hand, I think they are still available from
    (I added the link to the post too) -gd]

    Posted by: Nick at December 20,2017 10:56
    Post your own response

    Each comment is manually screened for the presence of appropriate and substantive content, due to a constant onslaught of comment-spam. This means there may be a delay before your comment appears.

    (Some kind of name is required, will be visible)

    Required, whatever you enter will be visible to other users.

    (Optional, used for "mailto" link)

    Your email address is not required, but if you insert it it will be displayed so people can contact you.

    Answer this question correctly to demonstrate that you are not a dumb spambot.

    The title for your comment.

    Your comment goes here. All relevant comments are welcome, except for those that simply promote an irrelevant product or else are used to fraudulently inflate the link count to an irrelevant web page. They appear after moderation. Don't forget to also fill in the captcha below or your text will be rejected automatically!

    You must answer this question to prove you are human
    which has the least friendly public image: 1:collie, 2:beagle, 3:doberman, 4:dachsund, 5:dalmatian?

    Answer this question correctly to demonstrate that you are not a dumb spambot.