Back to back fxs-fxo config

[ereyes]

Hello , I need a example for configure two 3640 back to back with fxs to fxo. voip-a---3640-fxs-fxo-3640--voip-b. My problem is when call from voip-a to the voip-b , and recive disconnect from voip-b , in the voip-a hear ringback all time

[paolo bevilacqua]

This is typical of fxo/fxs. Look at:

http://cisco.com/en/US/tech/tk652/tk653/technologies_tech_note09186a00800ae2d1.shtml

on CCO.

Try configuring both ports for ground start or another disconnection supervision as explained in the document.

[ereyes]

I see this later but I have loop-start configured .

Need change to Ground?

[paolo bevilacqua]

Have you read the document? It will explain you why without supervision your lines are going to remain stuck all the time. So, either ground-start, or other disconnection supervision must be configured.