SIP not registering on Cisco Router

Hello everyone,

I’m new to SIP and I’m trying to set up a SIP trunk using my Cisco 2811. I have enclosed the config and debug messages. I am sending Register invites but am not receiving anything back. Anybody with experience with setting up SIP on Cisco is greatly appreciated.

credentials username XXXXXXX password XXXXXXXX realm
no remote-party-id
retry invite 5
retry register 5
timers connect 100
timers register 100
registrar expires 3600
permit hostname

*Jul 23 20:09:26.098: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Via: SIP/2.0/UDP;branch=z9hG4bK4C017BC
From: sip:[email protected];tag=4FF0BA4-1CBF
To: sip:[email protected]
Date: Fri, 23 Jul 2010 20:09:26 GMT
Call-ID: 6B10034-95CD11DF-8047D6CE-BC0416A4
User-Agent: Cisco-SIPGateway/IOS-12.x
Max-Forwards: 70
Timestamp: 1279915766
Contact: sip:[email protected]:5060
Expires: 3600
Content-Length: 0

VOIP_ROUTER_1#show sip-ua register status
Line peer expires(sec) registered
================================ ========== ============ ==========
3d7cc614 -1 28 no
VOIP_ROUTER_1#show sip
% Incomplete command.

VOIP_ROUTER_1#show sip ?
calls Display Active SIP Calls
connections Display SIP Connections
map Display SIP status code to PSTN cause mapping table & vice versa
min-se Display Min-SE value
mwi Display SIP MWI server info
register Display SIP Register status
retry Display SIP Protocol Retry Counts
service Display SIP submode Shutdown status
statistics Display SIP UA Statistics
status Display SIP UA Listener Status
timers Display SIP Protocol Timers

VOIP_ROUTER_1#show sip status
SIP User Agent Status
SIP User Agent for UDP : ENABLED
SIP User Agent for TCP : ENABLED

SIP User Agent for TLS over TCP : ENABLED
SIP User Agent bind status(signaling): ENABLED
SIP User Agent bind status(media): ENABLED
SIP early-media for 180 responses with SDP: ENABLED
SIP max-forwards : 70
SIP DNS SRV version: 2 (rfc 2782)
NAT Settings for the SIP-UA
Role in SDP: NONE
Check media source packets: DISABLED
Maximum duration for a telephone-event in NOTIFYs: 2000 ms
Redirection (3xx) message handling: ENABLED
Reason Header will override Response/Request Codes: DISABLED
Out-of-dialog Refer: DISABLED
Presence support is DISABLED
protocol mode is ipv4

SDP application configuration:
Version line (v=) required
Owner line (o=) required
Timespec line (t=) required
Media supported: audio video image
Network types supported: IN
Address types supported: IP4 IP6
Transport types supported: RTP/AVP udptl

VOIP_ROUTER_1#show sip service
SIP Service is up

Looks set up and registered. What are trying to accomplish ? Are you using CME or is there a FreePBX System in the mix somewhere ?