• SIP trunk is limited to the used of codec
• All media to/from SIP trunk is terminate on MTP

• Configure source interface for SIP messages

voice service voip
  sip
    bind all source-interface Fa0/0.20

• Reduce timer for faster failover
  • Send SIP invite 3 times max (1 initial + 2 retries)
  • Wait 300ms for each trying

sip-ua
  retry invite 2
  timers trying 300

• Configure Dial Peer

dial-peer voice 1 voip
  destination-pattern 212394...
  session protocol sipv2
  session target ipv4:<cucm-sub>
  voice-class codec 1
  dtmf-relay rtp-nte
  no vad

• Display active call inbound and outbound dial peer
• In the example below
  • pid:5000 = inbound dial peer 5000
  • pid:91212 = outbound dial peer 91212

Router# show call active voice brief
...
Telephony call-legs: 1
SIP call-legs: 1
H323 call-legs: 0
Call agent controlled call-legs: 0
SCCP call-legs: 0
Multicast call-legs: 0
Total call-legs: 2
1383 : 280 920799800ms.1 +1960 pid:5000 Answer 2123945001 active
 dur 00:00:06 tx:343/54880 rx:343/54880
 IP 192.168.100.205:24598 SRTP: off rtt:35ms pl:4850/0ms lost:0/1/0 delay:55/55/75ms g711ulaw TextRelay: off
 media inactive detected:n media contrl rcvd:n/a timestamp:n/a
 long duration call detected:n long duration call duration:n/a timestamp:n/a
1383 : 281 920799830ms.1 +1930 pid:91212 Originate 912123942123 active
 dur 00:00:06 tx:344/57792 rx:442/70720
 Tele 0/0/0:23 (281) [0/0/0.10] tx:6870/6870/0ms g711ulaw noise:-66 acom:40  i/0:-66/-39 dBm

Telephony call-legs: 1
SIP call-legs: 1
H323 call-legs: 0
Call agent controlled call-legs: 0
SCCP call-legs: 0
Multicast call-legs: 0
Total call-legs: 2

Router#

• Real time display of dialpeer matching

Router# debug voip dialpeer
...
Sep 25 00:35:55.963: //-1/B19F88CA81AA/DPM/dpAssociateIncomingPeerCore:
   Calling Number=2123945001, Called Number=912123942123, Voice-Interface=0x0,
   Timeout=TRUE, Peer Encap Type=ENCAP_VOIP, Peer Search Type=PEER_TYPE_VOICE,
   Peer Info Type=DIALPEER_INFO_SPEECH
Sep 25 00:35:55.963: //-1/B19F88CA81AA/DPM/dpAssociateIncomingPeerCore:
   Result=Success(0) after DP_MATCH_ORIGINATE; Incoming Dial-peer=5000
Sep 25 00:35:55.967: //-1/B19F88CA81AA/DPM/dpMatchPeersCore:
   Calling Number=, Called Number=912123942123, Peer Info Type=DIALPEER_INFO_SPEECH
Sep 25 00:35:55.967: //-1/B19F88CA81AA/DPM/dpMatchPeersCore:
   Match Rule=DP_MATCH_DEST; Called Number=912123942123
Sep 25 00:35:55.967: //-1/B19F88CA81AA/DPM/dpMatchPeersCore:
   Result=Success(0) after DP_MATCH_DEST
Sep 25 00:35:55.967: //-1/B19F88CA81AA/DPM/dpMatchPeersMoreArg:
   Result=SUCCESS(0) 
   List of Matched Outgoing Dial-peer(s): 
     1: Dial-peer Tag=91212
...
Router# 

• Debug SIP messages

Router# debug ccsip messages

Sep 25 00:37:27.924: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Received: 
INVITE sip:912123942123@10.80.103.1:5060 SIP/2.0
Date: Sat, 25 Sep 2010 00:37:27 GMT
Call-Info: <sip:10.80.101.72:5060>;method="NOTIFY;Event=telephone-event;Duration=500"
Allow: INVITE, OPTIONS, INFO, BYE, CANCEL, ACK, PRACK, UPDATE, REFER, SUBSCRIBE, NOTIFY
From: "Hub CIPC" <sip:2123945001@10.80.101.72>;tag=7d2b5333-55a2-4a50-8e9e-054166bd5774-56445489
Allow-Events: presence, kpml
P-Asserted-Identity: "Hub CIPC" <sip:2123945001@10.80.101.72>
Supported: timer,resource-priority,replaces
Min-SE:  1800
Remote-Party-ID: "Hub CIPC" <sip:2123945001@10.80.101.72>;party=calling;screen=yes;privacy=off
Content-Length: 0
User-Agent: Cisco-CUCM7.0
To: <sip:912123942123@10.80.103.1>
Contact: <sip:2123945001@10.80.101.72:5060;transport=tcp>
Expires: 180
Call-ID: 11150300-c9d14447-e13-4865500a@10.80.101.72
Via: SIP/2.0/TCP 10.80.101.72:5060;branch=z9hG4bK6a4ccd9a10
CSeq: 101 INVITE
Session-Expires:  1800
Max-Forwards: 70

Sep 25 00:37:27.932: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Sent: 
SIP/2.0 100 Trying
Date: Sat, 25 Sep 2010 00:37:27 GMT
From: "Hub CIPC" <sip:2123945001@10.80.101.72>;tag=7d2b5333-55a2-4a50-8e9e-054166bd5774-56445489
Allow-Events: telephone-event
Content-Length: 0
To: <sip:912123942123@10.80.103.1>
Call-ID: 11150300-c9d14447-e13-4865500a@10.80.101.72
Via: SIP/2.0/TCP 10.80.101.72:5060;branch=z9hG4bK6a4ccd9a10
CSeq: 101 INVITE
Server: Cisco-SIPGateway/IOS-12.x

Router#