Avaya License requirement :
1- IP Office essential edition
2- SIP Trunk license ( to trunk with 3CX )
3- PRI/SIP Channel license ( Trunk to your ISP with either SIP or PRI  )
AVAYA IP500 V2 IP : 192.168.8.42
Port : LAN2 (Here I used LAN2 and LAN1 is not using and not connected on N/W)
Proto:UDP
Port:5060
Codecs allowed :G711Ulaw
ISP PRI Trunk : XXXXX900-XXXX999 3CX IP : 192.168.8.241 Proto:UDP Port:5060 Codecs allowed :G711Ulaw Extension : 1XX Queues : 8XX
3CX Configurations
1)Create One SIP trunk in 3CX to Avaya .
SIP Trunk in New Trunk Generic SIP Trunk , 3cx by giving peer IP, No authentication

DID Inbound Route  :  for Call Center Queue

Set the DID 2000 to the destination Queue 800

** Here, While receiving calls,  The agents can see caller as 50616209:800(50616209) like this. So To make it simple as 50616209,Do the following.

**–>In Parameters, Search for CID and you’ll get two options called APPENDCIDQUEUE and PREPENDNAMETOCID. Set both values to zero.

Outbound Route 1:  for Avaya extensions

Outbound Route 2 : for External Calls through Avaya

**While calling outside, 3CX will append 123 to the called_number. Ex:If an agent calls 44112233, Called number will be translated as 12344112233. So that avaya can identify call is coming from 3CX and need to be routed external through PRI.

Avaya Configurations

Create a SIP trunk without authentication

**ITSP domain name is the ip address of Avaya PBX.

**Check OOS must be off, Otherwise you may receive SIP error “service unavailable” on calling.

**Here LAN2 Selected, because Avaya IP address set on LAN2(192.168.8.42)

**Line Group ID for  Outgoing is 17, We will use this value while creating ARS (Outbound Routing).

**Use Audio Codec G711alaw and G711ulaw only

Inbound Route :  Receive calls  from main number 44197997 and pass to 3cx

Expand incoming call route and select DID 7997 and give destination 8200. Here “0” is the PRI Line Incoming group ID(0)

Then Avaya Check for an ARS matching 82000.

Avaya Matches an ARS with 8200 here;

**Finally, Incoming call received on DID 44197997 will be routed to 2000 (3CX Trunk Number)

Outbound Route for Making External Calls from 3CX agents

In 3CX, We have translated the outbound calls by prepending 123 to the called number and routed to Avaya. Now Avaya Will search for an ARS with which starts with  123 as prefix.

Here Line group ID:0 is the PRI outgoing group ID. So, the calls will be routed to PRI Trunk by removing prefix 123. Expression <NS”44197997”> is used to bind the source as 44197997 for External Calls.