[Asterisk-Users] Re: Again: 7920 Cisco IP Phone Skinny & SIP

[Siggi Langauf]

On Wed, 14 Jan 2004, Jan Czmok wrote:

> > It looks like chan_sccp is doing something at this pont that upsets the
> > 7920 so that it tries to fall back to SRST mode, before finally
> > re-registering.
>
> Okay, might be a reason. but what i saw on the display was:
>
> -> Registering to Callmanager
> -> Registered to Asterisk PBX
> -> Call ended.
>
> (without hitting any button).

Good point. When registering with CCM, it does send the SCCP messages for
going off-hook and back on-hook again, but it does not display the
prompts.
However, that's just cosmetics, I guess (CCM doesn't have anything like
the "Registered to ..." status message, and at the end of a call it always
displays "Your Options"

[...]
> Possible reason, looks like that, however i am surprised why the 7920
> reboots instead of just looking for another callmanager.

It does look for an SRST capable router first, then for up to 4 more
CallManagers and only then reboots.
(At least mine...)

[...]
> > There should also be a digitally signed version of that file
> > (cmterm_7920.*.sbn), which the phone probably requires.
>
> nope. no sbn. according to my cisco source the file is not signed.

Funny, that would be the first phone with unsigned firmware.
But I'll double-check after the next firmware update.

> > > Some additional info:
> > > ---------------------
> > > The 7920 is requesting cmterm_7920.3.3-01-02-021^J.bin
> > > (so with an Ctrl-J in it), so you have to rename the file.
> >
> > You'd better remove the trailing Ctrl-J from OS7920.TXT, then (or stop
> > using editors that insist on adding one).
>
> i did, i use vi as editor. i was also surprised, but this is coming from
> the phone ( i did extensive tethereal and tcpdump watching) :-)

Umm, vi is notoriously adding Linefeeds at the end of file.
Try "echo -n  cmterm_7920.3.3-01-02-021 >/tftpboot/OS7920.TXT" or use a
decent editor!

[...]
> > > I tried to use some 7960 images, but did not succeed :-(
> >
> > Of course not, it's totally different hardware.
>
> is it ? the cmterm image is nearly exactly 2 times the 7960 phone, so i
> suspect one lower part of the image for the new functions and the rest
> for the "normal" 79xx image.

nah!
Never.
The 7920 doesn't have any support for XML-Services, for example. And I
doubt that the Wireless hardware is in any way similar to the Ethernet
switch in the 7960.

[...]
> How can i help ? Just sit back isnt appropate for me :-)

*shrug*
Well, you could try to sniff the phone registering with CallManager
(Express) and Asterisk during registration with chan_sccp.
Maybe you'll see the difference that we're unable to spot.

> > Meanwhile, you can register your 7920 with CallManager Express and connect
> > that to asterisk via chan_oh323. (Note: chan_h323 will most likely not
> > work, at least if you need two-way audio ;)
> >
> Hmm. Might be one way to use CME. Will see..

Oh, wait!
CME should come with a SIP capable router. Prolly better to use SIP, then.

Cheers,
	Siggi