I need help getting back to back T1/E1 working please.  I have been trying to create a simple lab where 2 CME routers can dial between the phone each one has registered.  These phones can call each other over a frame-relay link so I'm sure my problems are related to dial peer config or controller configs.
Here is my basic dial peer and controller configs:
R1
network-clock-participate wic 0
dial-peer voice 1 pots
destination-pattern 2...
port 0/0/0:23
ephone 1
button 1:1
ephone-dn  1  dual-line
number 1001
interface Serial0/0/0:23
no ip address
encapsulation hdlc
isdn switch-type primary-ni
isdn incoming-voice voice
isdn protocol-emulate network
isdn incoming-voice voice
!
R2
network-clock-participate wic 0
dial-peer voice 1 pots
destination-pattern 1...
port 0/0/0:23
ephone 1
button 1:1
ephone-dn  1  dual-line
number 2001
interface Serial0/0/0:23
no ip address
encapsulation hdlc
isdn switch-type primary-ni
isdn incoming-voice voice
isdn protocol-emulate network
isdn incoming-voice voice
!
When I try to call between phones I get the invalid number tone and I can see from debugs that I have no matching outgoing dial peer but I don't understand why.  If I simply change the dial-peer 1 ports/voip type and the 'port port 0/0/0:23' statement to session target ipv4

.x.x.x the calls work.  I have also tried with various permutations of commands like the 
isdn incoming-voice voice and 
isdn protocol-emulate network under the t1 serial interfaces but nothing has worked so far.
Any help you can offer will be much appreciated.