Conference between Two IP Phones (g729) and 3rd Party droped

[R A]

Dears 
I have these scenarios with different result  


1- 1st scenario  (Conference success)

IP Phones ----CUCM----SIP GW---PRI----PSTN

IP Phone A (Region A)  has call with IP Phone B (Region B) using g729 codec for this call , then make conference with PSTN Number using codec g729 and conference success .

2- 2st scenario  (Conference failed)

IP Phones ----CUCM----H323 GW-------Avaya PBX

IP Phone A (Region A)  has call with IP Phone B (Region B) using g729 codec for this call , then make conference with Avaya  Extension using codec g729 and conference failed

Please note that
Calls between any IP Phone and Avaya extension use g729 Codec.
All IP Phones has MRGL with conference bridge and transcoder
H323 VG between CUCM and Avaya has MTP required.

3-3rd scenario 
Phone A  has call with PSTN number using Codec g729 then try to make conference with avaya extension but Conf failed.
Please check attached  sdl FILES FOR third scenario 
Phone A number is 6668
PSTN number is 01018868XXX
Avaya Extenstion  962

Please Advice

[Mohammed al Baqari]

Hi,

Can you try to insert an MTP for H323 and use FastStart ?

[R A]

Hello Mohamed
we already use MTP and fast start for H323 VG as required from avaya side 

[Mohammed al Baqari]

Are you confident that the CFB used us hardware not software.

When you place the first call in the call conference check the command show
sccp conn on the router to see if CFB is allocated and conference.