Re: Selection of media (m=) at MG

well spotted, thus just a single media configuration ('Clearmode') would be already sufficient to emulate that ISDN bearer service

PS
Your previous email was related to ISDN-to-SIP interworking at call control level, a subject which is out of scope of MEGACO.
Thus, something for SIPPING, SIP-IMPLEMENTERS, ... (or TISPAN WG3 list) in my understanding. 

> -----Original Message-----
> From: Javi Muñoz [mailto:[email protected]] 
> Sent: Mittwoch, 30. November 2011 18:13
> To: [email protected]
> Cc: Schwarz, Albrecht (Albrecht)
> Subject: Re: [Megaco] Selection of media (m=) at MG
> 
> A second comment,
> 
> If:
> >>     a) TGW: no impact, because tone/announcement inserted by ISDN 
> >> local exchange (terminating Q.931); TGW needs just 
> clearmode support
> 
> (I agree)
> 
> then, why?
> >> E.g., MGC
> >> ->  call establishment phase: IF tones/announcements THEN H.248
> >> Command.req for tone/announcement control plus media configuration 
> >> with voice codec
> 
> That "media configuration with voice codec" (G.711) would be 
> done at the MeGaCo termination of the IP side of the MG, not 
> at the termination of the ISDN side. If tone/announcement is 
> inserted (in the UNI ISDN) by this MG, the termination of the 
> IP side of the MG would not be used, so that "voice codec" 
> would not be relevant (no media would be transported over the 
> IP network).
> 
> am I wrong?
> 
> Regards,
> 
> Javi
>