[Asterisk-Users] [patch] fix libpri problem in Q931_INFORMATION handling

[Peter Svensson]

On Thu, 17 Feb 2005, Deti Fliegl wrote:

> Peter Svensson wrote:
> > Asterisk only expects INFORMATION elements when expecting overlap digits
> > (i.e. before CONNECT, PROCEEDING etc). After that it expects digits as
> > inline dtmf.
> Yep - but ISDN phones normally do not encode inline DTMF. Therefor 
> Keypad information can be sent.

Ok, then INFORMATION with keypad IE needs to be handled differently from 
IE called number.

> > According to Q.931 called party address IEs in the INFORMATION message 
> > should only be sent during overlap digit transmission, which ends when 
> > PROCEEDING is sent. 
> Well I have read the Q.931 specification too but for eg. Siemens HiCom 
> PBXs and phones use keypad IEs within a connected call and no DTMF. This 
> leads me to at least invent a new configuration parameter for ignoring 
> the call state when receiving such IEs.

I read the ets 300 403 01 spec as well as a more reacent revision of the 
Q.931 spec. Q.931 allows the keypad IE to signal called party number 
(during call setup) or to convey supplementary service information (pushed 
digits similar to dtmf). Q.931 allows the called party number IE to signal 
called party digits during call setup. 

The EuroISDN spec. in ets 300 403 01 is stricter - the keypad IE can not 
be used for overlap digits, only after the call setup. 

Are the digits you send encoded as Keypad IE? In that case a setting to 
allow keypad IE digits to always be accepted as dtmf digits may be 
the best solution. 

Peter