Based below architect, am design how we have to use this architect.
Let us discus with five cases as above architect shows.
1) In Incoming calls from providers to OpenSER Main Server
2) Outbound calls from OpenSER to providers [ may be PSTN or international
or national or STD ] means internal users to outbound calls
3) Internal to Internal outbound calls
4) To-Fro between the IAX channels and SIP channels
5) Ooh323 channels to SIP or IAX channels
SIP channels will register to OpenSER. Here there were two openser servers. One
openser main server and openser proxy for ata;s and softphones. In openser
Subscribers are users details to register into server.
Providers will register to OpenSER Main Servers and SIP Devices will register
OpenSER.
IAX channels will to Asterisk server, is no problems.

We have consider mainly the Billing system of this architect.
So, I absorb Database server is centralized of all Servers. That was includes in same
system. Here you are using the MOR billing system, which is nothing but like
A2billing.
Here by am designing the above architect in individuals parts, which I have mention
above. Cases.
1) Internal to Internal User Agents Outbound calls ( with Billing system ).
OpenSER server
OpenSER MAIN Server
for ATA and SP
2
1
User Agent 1
5
3
4
6
User Agent 2
MOR Billing System and Database center .
User Agent 1 and 2 are registered to OpenSER server (blue colour). When they want to
calls each other which shown above figure.

2) IAX Channels to SIP Channels with MOR Billing System also include in this
scenario.
Asterisk Server with IAX Channels , and PBX Server,
MOR Billing system.
User Agent1 IAX Channel
OPENSER MAIN
SERVER.
openSER server for
ATA and Softphones
User Agent SIP channels
2,2 ) SIP channels to IAX Channels with MOR Billing Also.

OpenSER Server for
ATA’s and Softfone
11
SIP Channels OpenSER Main server
2
2
3
5 4 Mor Billing System
6
IAX Channels ,
Asteriks Server & pbx server
IAX channels
3) Outbound calls for Sip Channels,
OpenSER server for ATA OpenSER Main Sever
2 3
1
SIP USER AGENT
5
4
MOR Billing
Provider 1
Provider 3
Provider 2
5. OpenSER Main Server will which provider to need to send appropriate
provider servers based on the DID, dialled number.
Or
OpenSER Main Servers will forwards to Gateways Servers. And the
Gateway Server will decide where this has to delivery to that provider.

4 ) Inbound to OpenSER Main Server from Providers.
In OpenSER Main Server
Providers
OPENSER MAIN SERVER
1.1
1.2
OPENSER SERVER
For ATA’s & SoftPhone
ASTERISK IAX SERVER
2 2
IAX UA
SIP UA
will decide the RRUI is IAX or SIP channels user, base the on RRUI List in
OPENSER MAIN SERVER.