[asterisk-users] Nortel pbx & dtmf issues

[Ernest Byaruhanga]

>> I see from the archives that the issue of nortel handsets not
>> sending dtmf tones to asterisk has been discussed a couple of times,
>> but there is something I quite havent seen answered yet.
>>
>> Is this dtmf issue a problem with the nortel handsets or the PBX
>> itself? If the handset were changed to another one, would this issue
>> be solved? Or must the PBX be changed completely?
> 
> The only issue that I've experienced with respect to DTMF and a Nortel
> PBX is when using SIP trunking.  Nortel used/uses (newer versions of
> CS1000 software, 5.0 and newer IIRC, can use RFC2833-based DTMF) a
> proprietary SIP INFO-based DTMF.  As it stands, Asterisk is capable of
> receiving and interpreting those messages properly.  But sending DTMF to
> the Nortel is an issue without code modification.
> 
> If you have a specific need for that, the changes themselves are fairly
> trivial, and I can detail those for you if you'd like.  I might even
> have a patch laying around that would work or could be made to work,
> since we needed to integrate into an older version of the CS1000
> software (since upgraded, so our current system passes DTMF via
> RFC2833).

Basically, the only issue I have is that the nortel phones do not
send dtmf signals to fxo on asterisk. I asked users to use the
"feature 808" on the phones to force the phone to generate "long
tones", and it all looks OK.

My only issue the "inconvenience" this puts on the users, and I
would like to see if wither:

a. Asterisk can understand the normal tones from the nortel handsets
without invoking the "long tones" feature manually, or
b. the nortel PBX can be configured to generate long tones for these
handsets directly.

thanks
eb