Cannot Get SIP Phones Working Behind Cisco 857 ADSL NAT Router

Experts,

Have installed a cisco ADSL 857 router as per config below. I've little experience of getting SIP phones working and I can't do it with this router. I ahve swapped it out temporarily with the ISP's own router ( A horrible BT 2Wire ) and the SIP phones work fine, problem is, the SIP provider won't support their phones unless they go through a cisco router! Arghh...

The router logs on to the internet fine and NAT works ok - can browse the web / download files e.t.c.

Can anyone help?


version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname 123456
!
boot-start-marker
boot-end-marker
!
logging buffered 51200 warnings
enable password 7 ABC123
!
no aaa new-model
!
crypto pki trustpoint TP-self-signed-2436944224
 enrollment selfsigned
 subject-name cn=IOS-Self-Signed-Certificate-2436944224
 revocation-check none
 rsakeypair TP-self-signed-2436944224
!
crypto pki certificate chain TP-self-signed-2436944224
 certificate self-signed 01 nvram:IOS-Self-Sig#4.cer
!
dot11 ssid XYZ1
   authentication open
   authentication key-management wpa
   wpa-psk ascii 7 XYZ1
!
no ip source-route
no ip dhcp use vrf connected
ip dhcp excluded-address 192.168.11.1
!
ip dhcp pool sdm-pool
   import all
   network 192.168.11.0 255.255.255.0
   default-router 192.168.11.1
   dns-server 192.168.11.1
   lease 3
!
!
ip cef
ip inspect name inout https
ip inspect name inout pptp
ip inspect name inout dns
ip inspect name inout telnet
ip inspect name inout sip
ip inspect name inout sip-tls
ip inspect name inout tcp
ip inspect name inout udp
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
ip domain lookup source-interface Dialer0
ip domain name customer.local
ip name-server 208.67.222.222
ip name-server 208.67.220.220
!
password encryption aes
!
!
!
bridge irb
!
!
interface ATM0
 no ip address
 no atm ilmi-keepalive
 dsl operating-mode auto
!
interface ATM0.1 point-to-point
 description adsl$ES_WAN$
 no ip redirects
 no ip unreachables
 ip virtual-reassembly
 pvc 0/38
  encapsulation aal5mux ppp dialer
  dialer pool-member 1
 !
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface Dot11Radio0
 no ip address
 !
 encryption mode ciphers tkip
 !
 ssid XYZ1
 !
 speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0 54.0
 station-role root
 bridge-group 1
 bridge-group 1 subscriber-loop-control
 bridge-group 1 spanning-disabled
 bridge-group 1 block-unknown-source
 no bridge-group 1 source-learning
 no bridge-group 1 unicast-flooding
!
interface Vlan1
 description $ETH-SW-LAUNCH$$INTF-INFO-HWIC 4ESW$
 no ip address
 bridge-group 1
!
interface Dialer0
 mtu 1452
 ip address negotiated
 ip access-group 121 in
 ip inspect inout out
 ip nat outside
 ip virtual-reassembly
 encapsulation ppp
 dialer pool 1
 dialer-group 1
 no cdp enable
 ppp authentication chap pap callin
 ppp chap hostname 123456
 ppp chap password 7 123456
 ppp pap sent-username 123456 password 7 123456
!
interface BVI1
 ip address 192.168.11.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer0
!
ip http server
ip http access-class 23
ip http authentication local
ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
ip dns server
ip nat inside source list 101 interface Dialer0 overload
!
access-list 23 permit 192.168.0.0 0.0.255.255
access-list 101 permit ip 192.168.11.0 0.0.0.255 any
access-list 121 permit icmp any any echo-reply
access-list 121 permit tcp host 208.67.222.222 any eq domain
access-list 121 permit udp host 208.67.222.222 any eq domain
access-list 121 permit udp host 208.67.220.220 any eq domain
access-list 121 permit tcp host 208.67.220.220 any eq domain

no cdp run
!
control-plane
!
bridge 1 protocol ieee
bridge 1 route ip
!
line con 0
 password 7 ABC123
 login
 no modem enable
line aux 0
line vty 0 4
 access-class 23 in
 privilege level 0
 password 7 ABC123
 login
 transport input telnet ssh
!
scheduler max-task-time 5000
end