We have two call manager express routers (2801 and 2811) connected through a WAN Connection. The 2801 router is acting as a voice gateway at the head office and connects 10 FXO ports to a Leagcy PBX. No IP Phones are connected with the 2801.
The 2811 has 10 IP Phones connected. We want to be able to have an FXO Line dedicated to each IP Phone at the remote site. Incoming calls are being routed to the Remote CME by using the connection plar xxxx command on the head office voice port accordingly.
The problem is with Outgoing calls from the IP Phones. We want that the same FXO port is used everytime that we want to access an outside line. This is so that users at the head office will know who is calling them and also we need this for the callback function on the legacy PBX to work properly.
I am achieving this result currently by specifying voice translation rules on the remote CME. A different set of rule is applied to every ephone so the before the number is passed to the Head office CME, a number (unique to the ephone) is appended to the number dialed and then it is passed to the Head CME. The head CME then has dial peers configured for every possible appended number which in turn strips this appended number and passes the digits to the appropriate voice port.
This is working fine, however I am feeling this solution a bit too dirty and too complicated, simply to map always the same FXO port to an ephone. I am also not happy with the fact the when you dial a number, you will see the extra appended number on the display of the IP Phone.
Is there a more clean and easy way to achieve what I require. Maybe using the Head Router as an MGCP gateway will be an idea?