Trunk Group: Q931 Signal variant

[DS_Eire]

Hi,

Could someone please explain the difference between the following 2 parameters for Q931 Signal variant - is there a difference in the signalling etc
ISDN all countries
ABC-F

OXE-----3rd party PBX----Conference server

Q931 Signal variant set to ABC-F
I had an ABC-F trunk configured from a OXE 9.1 to an external 3rd party gateway which then had a SIP trunk to a conferencing server - calls to this conference server worked fine.
I upgraded to OXE 10.0 and started to see problems with this call flow - once the conference server sent a reinvite on getting into a conference, the OXE would send a BYE.

Q931 Signal variant set to ISDN all countries
I then deleted the above trunk and created a trunk with Q931 Signal variant set to "ISDN all countries". Now I do not see the above issue, after the conference server sends a reinvite the call remains up.

Could someone please explain the difference between both Signal Variants and if possible maybe explain why the ISDN parameter seems to work better.

Thanks

[enio.eltz]

Hi DS_Eire

First of all, I post here because I want to follow this post.
I don't have a great knowledge about ABC-F, but I am going to dare write something about this.

I think ABC-F you must use just with another OXE in the network through SIP, T2, etc. I think ABC-F is a owner protocol of the OXE. As you have a 3rd party system, the use of ISDN all countries must be better than ABC-F because ISDN all countries might be a generic protocol. Because of this ISDN worked better for you.

I hope my reasoning were right and help you.

Best regards.

[DS_Eire]

Hi Enio,

Thank you for your response. What you are saying makes sense to me also. Since writing this post I was talking to an engineer who was working on my system and they also said the same thing, that ABC-F is mostly used for OXE---OXE trunks but can in some cases work with other vendors. The ISDN option as you state is probably a more generic variant that most vendors would adhere to.

Thanks

[enio.eltz]

Hi DS_Eire

Yes, and in your case, probably, it is necessary only a simple communication between OXE <--> 3rd party.

[vad]

One question - ABC-F, ISDN, QSIG - we say about T2 or SIP TG (TDM or VoIP)?

[DS_Eire]

Hi Vad.

This will be a VOIP trunk, the following parameters are set on this trunk

Trunk Group Type + T2
Q931 Signal variant + ISDN all countries
T2 Specification + SIP

The rest are default values - do you see a problem with this configuration?

Thanks