SIP Trunk on multiple location - Remote Sites with GD3-CS2

[damnedi]

Hi,
I have an issue I'm wondering if it's possible using OXE architecture

here is a quick schema of it (check the attachment).

OXE-SIP-TRUNK.png

Each of the site has a direct gateway and dedicated possible connection to SIP provider.


In my understanding, all SIP External Trunk Group Communications are managed through the Main OXE Site.
Which means the main OXE registers the 3 differents trunk sips on my schema.

So, in case of trouble on any of the private IP link, The CS2 on the remote site boots up and tries to register too the sip trunk.
Which would fail. Cause the trunks would be registered 2 times.

My main question is : Is this architecture possible ? How to register "Sip trunk2" and "Sip Trunk3" 'locally' on each site, using their dedicated link to SIP Provider?
Any ideas?

Thx in advance !

[damnedi]

No one ever tested / had this problem?

[alaint73]

can you provide more explanations about the issue you are trying to resolve? do the CS2 in your diagram depict the PCS ( Passive Call Server?) do you have one or several SBC ( session border controller) in your architecture?.

please advise

[cavagnaro]

Why would it fail? As session from Appliance expires then you will be able to Register on the PCS as well. Also it is totally possible to register from 2 different sites as a single object. On the remote SIP server you will have 2 endpoints associated to a single object. SIP server should accept them both.
Best thing to do for you is to try it as each scenario is completely unique. We don't know your provider capabilities nor your whole architecture. We can help on ideas but not final design solutions.

[damnedi]

Hi,
Thx alaint73 and cavagnaro for your answers.

Alaint73, the CS2 in my diagrams refers to PCS, on both remote sites.
Only one SBC, which is actually on the public side.

Cavagnero, the issue is more twisted then this. Here is the detailled explanation, with an updated schematic.

oxe-sip-trunk2.png

The initial idea is :

- 1 site = 1 sip trunk = Bandwith dedicated per site per sip trunk.
- Main Site : its SIP trunk, communications goes through default route on main site
- Site 1 : its SIP trunk, communication goes througgh default route on site1
- Site 2 : its SIP trunk, communication goes througgh default route on site2
- Site2Site communication, going through private dedicated links.

My problem is, in my understanding, that in 'nominal state', with no pcs active, the sip registration would be done through the main OXE, and so communications will go through the default gateway on the main site.
In 'degraded' state, PCS will take over on the remote site, and register with the SBC/Sip Provider, while main site would still be logged on, which could cause eventually troubles.

So my main 2 problem towards this are :
- bandwith used on main site in nominal state and not on the remote site for SIP registration and RTP flow, and would be desirable to use local bandwith for RTP flow on each site,
- dual and duplicated registration with main site, and degraded site at the same time in case of PCS take over,

The wonderful solution which would solve this problem is 'can I register a SIP trunk directly on a GD3/PCS, and use the gateway there for SIP trunk registration (External Gateway)?'
In all I read / searched / asked/ looked for, didn't find any positive / possible answer.
Won't solve the dual registration problem, but this can be workarounded with SIP Provider.

What do you think?