Home > Articles > Session Initiation Protocol

Session Initiation Protocol

  • Sample Chapter is provided courtesy of Cisco Press.
  • Date: Oct 16, 2006.

Troubleshooting Tools

If calls cannot be made between SIP gateways or over SIP trunks, dial peer configuration is one of the first places to check. Make sure that the dial peer is configured to use SIP and that both devices are using the same transport protocol and DTMF relay method. Make sure that destination patterns and session targets are correct, also.

Several show commands can troubleshoot and monitor the SIP UA function of the gateway. Example 4-12 lists them; options can vary by Cisco IOS and device.

Example 4-12. show sip-ua Command Options

SIP-GW#show sip-ua ?
  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

The show sip-ua connections {udp|tcp} command gives you information on active connections, including those with errors. To stop a problem connection, use the clear sip-ua {udp | tcp} [connection id number] [target ipv4: ip-address] command.

To ensure that the SIP is enabled on the gateway, use the show sip-ua service command. You should get the following result:

SIP-GW#show sip-ua service
SIP Service is up

The show sip-ua statistics command provides statistics on each type of method and response, errors, and total SIP traffic information. You can reset these counters with the clear sip-ua statistics command.

The show sip-ua status command can be useful in troubleshooting, also. Output from this command was shown previously in Example 4-13.

To debug SIP messages, use the debug ccsip command. This command has several options, as Example 4-13 shows. Use messages to see the SIP method and response messages, as shown previously in Example 4-1. The media option shows RTP information. Your options might vary by Cisco IOS and device.

Example 4-13. debug ccsip Command Options

SIP-GW#debug ccsip ?
  all        Enable all SIP debugging traces
  calls      Enable CCSIP SPI calls debugging trace
  error      Enable SIP error debugging trace
  events     Enable SIP events debugging trace
  info       Enable SIP info debugging trace
  media      Enable SIP media debugging trace
  messages   Enable CCSIP SPI messages debugging trace
  preauth    Enable SIP preauth debugging traces
  states     Enable CCSIP SPI states debugging trace
  transport  Enable SIP transport debugging traces
10. Case Study: Configuring SIP Between a Gateway and CallManager 5.x | Next Section Previous Section

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.