6 Replies Latest reply: Mar 14, 2011 9:58 PM by Adam McDonald RSS

    IP Phone IOS


      Hello all,

            is there a way to erase the IOS in my cisco 7911G and then load in a fresh copy of IOS? 

        • 1. Re: IP Phone IOS



          You can either upgrade your firmware to a newer version or restore your phone to factory settings. These are the only 2 options you've got.


          Is there a reason why you want to erase n reload the firmware? Are you facing any problems with the phone?



          • 2. Re: IP Phone IOS

            Vinci what happen is i wasnt getting the phone to boot and i followed some instructions from a site to do a factory reset but some how that didnt work and now when i plug in the phone all i see is the handset light flashes and then nothing more...

            • 3. Re: IP Phone IOS

              Hello i got the IOS to load by following another set of instructions, however i have another question, i currently have IOS 7.2 on my phones but cant seem to upgrade to 8.5, is it that i have to upgrade to another version before i move to 8.5?

              • 4. Re: IP Phone IOS

                Well, I am not aware if there about specifics of the upgrade from 7.2 to 8.5. However, the best place i would go for is the release notes.



                Let me know how it goes. I will learn from your issue.

                • 5. Re: IP Phone IOS

                  I agree with Vinci, those are your two options.


                  I have had a nearly identical problem, using 7940 phones and CME on a 2811 router.


                  I'll try to look up old reference material for my solution.  If I recall, it had something to do with firmware versions causing an issue.

                  • 6. Re: IP Phone IOS
                    Adam McDonald

                    Your phone is probably rejecting the higher version phone load due to an authentication fail. I've worked with some phone upgrade shortcuts in the past, but in the end you should upgrade your phone firmware one step at a time (i.e. 8-3-2s, upgrade to 8-4 and then 8-5). I also must point out that you must change the term.default file with each firmware version. I’ve seen some people that think they can upgrade without uploading the new term file. The term file tells the phone the names and order to load the firmware files being served up via tftp.

                    Issue these commands and yes I’d recommend capturing the output to a file for review.

                    debug tftp events

                    Terminal monitoring

                    Then restart the phone and watch the messages. The fastest way to reset a phone is settings key **#**

                    Watch the phone load and file transfer process. I wish there was an easier way… I get frustrated each time I forget and mail a new phone out and it turns up with an 8-3-2s phone load.

                    In addition to file type, you’ll need to watch your file loads for file extension. I’ve noticed some loads out there that require a .loads extension and some that do not. Even more frustration, some 7916 and 7914 modules will vary on needing a .SBN or not under the load command depending on what phone firmware revision you’re attempting to use.