Cisco IOS 12.4(15)T – A warning for all
A short while ago I discussed the merits of Cisco’s CallManager Express 4.0 software, over their previous 3.3 release which I had been using. It really was a big improvement, but alas there was still some functionality missing that I really required (namely the ‘blf-speed-dial’ command.)
So the hunt began, and seemingly not long before we’d started looking, Cisco had released IOS version 12.4(15)T, which indeed comes with CME 4.1 bundled in the appropriate voice-related featuresets. I chose this release, as the only alternative was an earlier X release. And I’m still quite un-sure of X releases, as it happens.
Now for the severe warning:
Do NOT attempt to register an Snom 360 SIP phone to the SIP registar with this release. We’ve tested a few non-Cisco SIP phones so far, all with varying degrees of success (the Grandstream GXP2000 worked well, though it’s far from usuable*), but the Snom actually caused the router to crash and reboot each time it attempted to register.
Strange but true – a SIP phone registering caused the router (a 2811) to bomb-out and restart at least six times before I realised what was going on. I guess there’s one reason why the more experienced Cisco geeks shy well away from T-train releases…
To make matters worse, I’ve found another strange, yet seemingly harmless bug with this new image. Whenever a call is made, and it doesn’t matter where it’s orginated or destined for; as soon as the call is answered the CLID is suffixed with seemingly random crap. Due to the fact that most of it is garbage, with the rest resembling bits of caller IDs from previous calls, I’d hazard a guess that this is some sort of memory over/underflow issue (but I’m no experienced programmer, so feel free to correct me.)
I’m also not sure whether it’s the IOS release, or CME 4.1 which is causing the problem. I’ve not had the 12.4(11)XJ3 release to test it with, and I’m more-likely to push fowards instead of backwards as there’s since been a newer IOS released with CME 4.2 and I’m hoping it will solve the problem. The only problem is, it’s another X release.
What I do know though, is that changing the 7960 firmware load makes no difference what-so-ever. I’ve tested 8.0(5.0) (which happens to be the recommended version for use with CME 4.1), 8.0(6.0) and even 8.0(4.0) with no change in behaviour. The only thing I can attest to is that the Grandstream SIP phone I’m using for testing purposes doesn’t exhibit the same problem. That’s one yay for SIP, at least.
If anyone out there is experiencing the same problem, then please let me know any possible solutions that I could test!
*The Grandstream can currently dial extensions registered to both CME, and our Asterisk gateway but as for calling externally – I merely receive a 403 error. Maybe I need to keep playing with it, but I don’t think Cisco’s implementation of SIP still particularly favourable…