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

[Jan Czmok]

Siggi Langauf (langausd at swt.uni-stuttgart.de) wrote:
> 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"

Okay, can you do a tcpdump/tethereal dump file of this ? was googling
around but only found one dumpfile for the 12SP+ which is (compared both
registrations) different than the 7920.

when i have the dump file i can further analyse this.

my idea would go this way:

original (currently) handling of sccp messages:

loop {
 check for commands
	do something
 break;
 ...
  check for commands
        do something
 break;
}

my idea: 

loop {
 check for registration message and IF from 7920 then
 function sccp_registration_7920;
 break;
 ...
 check for commands
        do something
 break;
 ...
}

in the sccp_registration i would then handle the registration for the
7920 how the callmanager is behaving.

> [...]
> > 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.
> 

how can i distinguish if it's signed or not ?

> > 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 did, but the phone still wants "cmterm_7920.3.3-01-02-021^J.bin" -

> > > > 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.

okay my doubt is: 1st part of the image is the basic stuff like xml and
a "boot loader" or emulator for the 7960mode in the next block of the
file there's the 7960 code.

watch the tftp boot process when it tries to download the file ...

> 
> [...]
> > 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.

i will do so if i have dumpfiles of successful registration.

> > 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.

i have several here available. i'll check... i got 2620, 3640 and 7200
with just ordinary cards but maybe enough for the testing...

--jan


-- 
Jan Czmok, Network Engineering & Support, Global Access Telecomm, Inc.
Ph.: +49 69 299896-35 - fax: +49 69 299896-40 - sip:13129*522 at inoc-dba.pch.net