Im currently building up my first CME voice lab - been working with Cisco kit a few years now but never got round to looking at the voice side of things.
Anyway, have got my hands on a 1751v with a VIC-2FXO-EU...and I already have an 877w ISR (with the PoE injector module) and finally I have a 7941 phone (I have a 7920 on its way from ebay!)
So...after a lot of head scratching I managed to get it all hooked up and implemented a basic dial plan config which allows me to place an outgoing call through the FXO onto my home phone line and also take inbound calls as well...
But...I only have one way voice going on (caller on the 7941 cannot hear the called party...but they can hear the person on the 7941).
Everywhere I have looked seems to suggest that its most likely a firewall issue - however I am at a loss to find where as I dont have any ACL's assigned to the Voice VLAN interfaces.
The connectivity is as follows
FXO is in the 1751v (CME), the router is then connected to one port on the 877 via a trunked link...(VLAN50 is data and 20 is voice). and the phone is connected to another port on the 877
I am attaching the (sanitised) configs from the 877w and the 1751v - Have a look and see if you can spot anything that I am missing (Im sure it will be something obvious for someone "in the know").
This will be your problem on the 1751V: "no ip routing".
In theory you could run the router without ip routing, but in practice you need it because the voice stack depends on it.
Throw a default route in there and you should be good to go.