[Asterisk-Users] Cisco 7960 + SIP

[Rich Adamson]

> I know this isn't strictly Asterisk, but I'm sure that there are more people
> here using the Cisco 7960 w/ SIP, so I thought I'd post here.
> 
> I've just bought a Cisco 7960 phone to use with Asterisk. It came with the
> CallManager image on it.
> 
> I've got the 4.4 SIP images (P0S3-04-4-00).
> 
> If I put "P0S3-04-4-00" in the OS79XX.TXT file, the phone downloads this
> fine (watching TFTP server debug).
> 
> It then proceeds to request P0S3-04-.bin. I don't know why. Naturally this
> file isn't found.
> 
> I tried renaming the file to P0S3-04-.bin. The phone then downloads around
> 80% before aborting.

I see from a later posting you have it running now, however for the purposes
of the archive (since I spent several days doing the same), I'm going to post
a couple of comments relative to changing 7960 images. I went through the same
steps that you're trying with two identical phones (both had identical firmware,
etc) and had problems with one but not the other.

Cisco has published a document "How to Convert a 7960 Call Manager Phone to a
SIP Phone and the Reverse Process", however the steps outlined are very
dated. In any case, the document is somewhat helpful. What the document does
not state is that one "must" start with early versions of Cisco's SIP code
and step through the version upgrades one at a time.

For example, start with a SIP image in the v2.x or early 3.x, then upgrade to
later releases, then upgrade to v4.4, etc.  At the v4.4 release, the phone is
sensitive to the size of the SIPdefault file and removing all the comment lines
from this file corrects that issue.

As I mentioned, I upgraded two identical 7960's. One phone accepted the v4.4
code with the comment lines, while the second failed repeatedly. After strungling
with it, someone on the list suggested removing the comment lines. I did so, and
it now consistently loads properly. The symptoms with this second phone indicated
the phone actually booted fine, read the appropriate TFTP files, and at the end
of loading the SIPdefault file it would quickly reboot, and repeated that process
forever. I had reloaded from v2, v3, then v4 several times but the only 
resolution that worked was removing the comment lines from SIPDefault.

Although Cisco also provides v5.2 and v5.3 code, the release notes warn the user
that once installed, there is "no way" to downgrade to v4.4 code. Given the problems
that I had getting v4.4 to load reliably, I have no intentions of moving to a code
level that makes it impossible to go back. Well, maybe just before I retire. ;)

Readers should be aware that v4.4 code uses the following tftp files (which are
all case sensitive):
 OS79XX.TXT
 SIPDefault
 POS3-04-4-00.bin
 SIP<your mac address>  (eg, SIP00036BABD123)
 RINGLIST.DAT
 dialplan.xml		(optional)
 ringer1.pcm		(optional)

Early versions of the SIP code did not require all of these, however if they
are in the tftp directory, it doesn't hurt the loading process.
  
Readers should also be aware that not all tftp server software function the same
way. We've used several Windows-based tftp servers that have had problems with
upper-lower case, filenames with unusual characters, proper handling of the last
packet transmitted, etc. Having a sniffer handy to monitor which files are actually
loaded and which have problems has been very handy (eg, ethereal is free along with
several others). Without the sniffer one can only guess at which files are not
properly loaded. (Obviously if the phone upgrades correctly, it's not needed at all.)

Since the tftp loading of these files is case sensitive, be very carefull 
with "0" (zero) and "O" (oh).

If you purchase a used 7960 that has been "locked" with an unknown password, it
is still possible to change the Network Configuration setting for DHCP and the
Alternate TFTP (change to Yes, then enter "your" tftp server's IP address)
from the front panel. The next reboot will use your dhcp IP address and your 
tftp server to obtain the files noted above, which in effect is the SIP upgrade. 
(Note there is a "phone_password" entry in the SIP<your mac> file starting 
around v3.2, and that will become the unlock password needed at the phone's 
front panel in order to make changes. Early versions of cisco's code used 
*## to unlock the front panel while later versions (starting with either v3.2 
or v4.4, forget which) uses the password as mentioned.)

I've repeated the above from memory, therefore if someone spots and error or
better way to deal with the 7960 SIP upgrade, feel free to suggest improvements.

The phone does function nicely with Asterisk, however the functionality is a
little different then what Cisco provides their Call Manager users.

Hope this helps someone...