Basic SIP Configuration
Table Of Contents
Basic SIP Configuration
Contents
Prerequisites for Basic SIP Configuration
Information About Basic SIP Configuration
SIP Register Support
SIP Redirect Processing Enhancement
Sending SIP 300 Multiple Choice Messages
How to Perform Basic SIP Configuration
Configuring SIP VoIP Services on a Cisco Gateway
Shut Down or Enable VoIP Service on Cisco Gateways
Shut Down or Enable VoIP Submodes on Cisco Gateways
Configuring SIP Register Support
Configuring SIP Redirect Processing Enhancement
Configure Call-Redirect Processing Enhancement
Configuring SIP 300 Multiple Choice Messages
Configuring Sending of SIP 300 Multiple Choice Messages
Configuring SIP Implementation Enhancements
Interaction with Forking Proxies
SIP Intra-Gateway Hairpinning
Verifying SIP Gateway Status
General Troubleshooting Tips
Configuration Examples for Basic SIP Configuration
SIP Register Support: Example
SIP Redirect Processing Enhancement: Examples
SIP 300 Multiple Choice Messages: Example
Additional References
Basic SIP Configuration
This chapter provides basic configuration information for the following features:
•

SIP Register Support
•

SIP Redirect Processing Enhancement
•

SIP 300 Multiple Choice Messages
•

SIP implementation enhancements:
–

Interaction with Forking Proxies
–

SIP Intra-Gateway Hairpinning
Feature History for SIP Register Support, SIP Redirect Processing Enhancement, and SIP 300 Multiple Choice Messages
Release | Modification |
12.2(15)ZJ | This feature was introduced. |
12.3(4)T | This feature was integrated into the release. |
Feature History for SIP Implementation Enhancements: Interaction with Forking Proxies and SIP Intra-Gateway Hairpinning
Release | Modification |
12.2(2)XB | These features were introduced. |
12.2(8)T | This feature were integrated into the release. |
Finding Support Information for Platforms and Cisco IOS Software Images
Contents
•

Prerequisites for Basic SIP Configuration
•

Information About Basic SIP Configuration
•

How to Perform Basic SIP Configuration
•

Configuration Examples for Basic SIP Configuration
•

Additional References
Prerequisites for Basic SIP Configuration
SIP Redirect Processing Enhancement Feature
•

Ensure that your SIP gateway supports 300 or 302 Redirect messages.
Information About Basic SIP Configuration
To perform basic SIP configuration tasks, you should understand the following concepts:
•

SIP Register Support
•

SIP Redirect Processing Enhancement
•

Sending SIP 300 Multiple Choice Messages
SIP Register Support
With H.323, Cisco IOS gateways can register E.164 numbers of a POTS dial peer with a gatekeeper, which informs the gatekeeper of a user's contact information. SIP gateways allow the same functionality, but with the registration taking place with a SIP proxy or registrar. SIP gateways allow registration of E.164 numbers to a SIP proxy or registrar on behalf of analog telephone voice ports (FXS), IP phone virtual voice ports (EFXS), and local SCCP phones.
When registering dial peers with an external registrar, you can also register with a secondary SIP proxy or registrar to provide redundancy. The secondary registration can be used if the primary registrar fails.
SIP gateways allow registration of E.164 numbers to a SIP proxy or registrar server on behalf of analog telephone voice ports (FXS), IP phone virtual voice ports (EFXS), and local SCCP phones. By default, SIP gateways do not generate SIP Register messages. The following tasks set up the gateway to register E.164 telephone numbers with an external SIP registrar.
Note 
There are no commands that allow registration between the H.323 and SIP protocols.
SIP Redirect Processing Enhancement
SIP Redirect Processing allows flexibility in the handling of incoming redirect or 3xx class of responses. Redirect responses can be enabled or disabled through the command-line interface, providing a benefit to service providers who deploy Cisco SIP gateways. Redirect processing is active by default, which means that SIP gateways handle incoming 3xx messages in compliance with RFC 2543. RFC 2543 states that redirect response messages are used by SIP user agents to initiate a new Invite when a user agent learns that a user has moved from a previously known location.
In accordance with RFC 2543-bis-04, the processing of 3xx redirection is as follows:
•

The uniform resource identifier (URI) of the redirected INVITE is updated to contain the new contact information provided by the 3
xx redirect message.
•

The transmitted CSeq number found in the CSeq header is increased by one. The new INVITE includes the updated CSeq.
•

The To, From, and Call ID headers that identify the call leg remain the same. The same Call ID gives consistency when capturing billing history.
•

The UAC retries the request at the new address given by the 3
xx Contact header field.
Redirect handling can be disabled by using the
no redirection command in SIP user-agent configuration mode. In this case, the user agent treats incoming 3
xx responses as 4
xx error class responses. The call is not redirected, and is instead released with the appropriate PSTN cause-code message.
Table 1 shows the mapping of 3
xx responses to 4
xx responses.
Table 1 Mapping of 3xx Responses to 4xx Responses
Redirection (3xx) Response Message | Mapping to 4xx (Client Error) Response |
300 Multiple choices | 410 Gone |
301 Moved Permanently | 410 Gone |
302 Moved Temporarily | 480 Temporarily Unavailable |
305 Use Proxy | 410 Gone |
380 Alternative Service | 410 Gone |
| 410 Gone |
SIP Redirect Processing generates call history information with appropriate release cause codes that maybe used for accounting or statistics purposes. When a 3xx response is mapped to 4xx class of response, the cause code stored in call history is based on the mapped 4xx response code.
Call redirection must be enabled on the gateway for SIP call transfer involving redirect servers to be successful.
The Cisco IOS voice gateway can also use call redirection if an incoming VoIP call matches an outbound VoIP dial peer. The gateway sends a 300 or 302 Redirect message to the call originator, allowing the originator to reestablish the call. Two commands allow you to enable the redirect functionality, globally or on a specific inbound dial peer: redirect ip2ip (dial-peer) and redirect ip2ip (voice service).
Sending SIP 300 Multiple Choice Messages
Originally, when a call was redirected, the SIP gateway would send a 302 Moved Temporarily message. The first longest match route on a gateway (dial-peer destination pattern) was used in the Contact header of the 302 message. Now, if multiple routes to a destination exist for a redirected number (multiple dial peers are matched), the SIP gateway sends a 300 Multiple Choice message, and the multiple routes in the Contact header are listed.
The redirect contact order command gives you the flexibility to choose the order in which routes appear in the Contact header.
How to Perform Basic SIP Configuration
This section contains the following procedures:
•

Configuring SIP VoIP Services on a Cisco Gateway
•

Configuring SIP Register Support
•

Configuring SIP Redirect Processing Enhancement
•
Configuring SIP 300 Multiple Choice Messages
•
Configuring SIP Implementation Enhancements
–
Interaction with Forking Proxies
–

SIP Intra-Gateway Hairpinning
•

Verifying SIP Gateway Status
Note 
For help with a procedure, see the verification and troubleshooting sections listed above.
Configuring SIP VoIP Services on a Cisco Gateway
This section contains the following procedures:
•

Shut Down or Enable VoIP Service on Cisco Gateways
•

Shut Down or Enable VoIP Submodes on Cisco Gateways
Shut Down or Enable VoIP Service on Cisco Gateways
To shut down or enable VoIP service on Cisco gateways, perform the following steps.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
voice service voip 4. 
[
no]
shutdown 5.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | voice service voip Example: Router(config)# voice service voip | Enters voice-service VoIP configuration mode. |
Step 4 | [no] shutdown [forced] Example: Router(config-voi-serv)# shutdown forced | Shuts down or enables VoIP call services. |
Step 5 | exit Example: Router(config-voi-serv)# exit | Exits the current mode. |
Shut Down or Enable VoIP Submodes on Cisco Gateways
To shut down or enable VoIP submodes on Cisco gateways, perform the following steps.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
voice service voip 4.
sip 5. 
[
no]
call service stop 6.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | voice service voip Example: Router(config)# voice service voip | Enters voice-service VoIP configuration mode. |
Step 4 | sip Example: Router(config-voi-serv)# sip | Enters SIP configuration mode. |
Step 5 | [no] call service stop [forced] [maintain-registration] Example: Router(conf-serv-sip)# call service stop maintain-registration | Shuts down or enables VoIP call services for the selected submode. |
Step 6 | exit Example: Router(conf-serv-sip)# exit | Exits the current mode. |
Configuring SIP Register Support
To configure SIP register support, perform the following steps.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
sip-ua 4.
registrar 5.
retry register 6.
timers register 7.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | sip-ua Example: Router(config)# sip-ua | Enters SIP user-agent configuration mode. |
Step 4 | registrar {dns:address | ipv4:destination-address} expires seconds [tcp] [secondary] Example: Router(config-sip-ua)# registrar ipv4:10.8.17.40 expires 3600 secondary | Registers E.164 numbers on behalf of analog telephone voice ports (FXS) and IP phone virtual voice ports (EFXS) with an external SIP proxy or SIP registrar server. Keywords and arguments are as follows: • dns:address—Domain-name server that resolves the name of the dial peer to receive calls. • ipv4:destination-address—IP address of the dial peer to receive calls. • expires seconds—Default registration time, in seconds. • tcp—Sets transport layer protocol to TCP. UDP is the default. • secondary—Specifies registration with a secondary SIP proxy or registrar for redundancy purposes. Optional. |
Step 5 | retry register number Example: Router(config-sip-ua)# retry register 10 | Use this command to set the total number of SIP Register messages that the gateway should send. The argument is as follows: • number—Number of Register message retries. Range: 1 to 10. Default: 10. |
Step 6 | timers register milliseconds Example: Router(config-sip-ua)# timers register 500 | Use this command to set how long the SIP user agent waits before sending register requests. The argument is as follows: • milliseconds—Waiting time, in ms. Range: 100 to 1000. Default: 500. |
Step 7 | exit Example: Router(config-sip-ua)# exit | Exits the current mode. |
Configuring SIP Redirect Processing Enhancement
This section provides the following information:
•

Configure Call-Redirect Processing Enhancement
•

Configuring SIP 300 Multiple Choice Messages
Configure Call-Redirect Processing Enhancement
Redirect processing using the redirection command is enabled by default. To disable and then reset redirect processing, perform the steps listed in this section:
•

Configuring Call-Redirect Processing Enhancement
IP-to-IP call redirection can be enabled globally or on a dial-peer basis. To configure, perform the steps listed in these sections:
•

Configuring Call Redirect to Support Calls Globally
•

Configuring Call Redirect to Support Calls on a Specific VoIP Dial Peer
Configuring Call-Redirect Processing Enhancement
To configure call-redirect processing enhancement, perform the following steps.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
sip-ua 4.
no redirection 5.
redirection 6.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | sip-ua Example: Router(config)# sip-ua | Enters SIP user-agent configuration mode. |
Step 4 | no redirection Example: Router(config-sip-ua)# no redirection | Disables redirect handling—causes the gateway to treat incoming 3xx responses as 4xx error class responses. |
Step 5 | redirection Example: Router(config-sip-ua)# redirection | Resets call redirection to work as specified in RFC 2543. The command default redirection also resets call redirection to work as specified in RFC 2543. |
Step 6 | exit Example: Router(config-sip-ua)# exit | Exits the current mode. |
Configuring Call Redirect to Support Calls Globally
To configure call redirect to support calls globally, perform the following steps.
Note 
To enable global IP-to-IP call redirection for all VoIP dial peers, use voice-service configuration mode. The default SIP application supports IP-to-IP redirection.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
voice service voip 4.
redirect ip2ip 5.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | voice service voip Example: Router(config)# voice service voip | Enters voice-service VoIP configuration mode. |
Step 4 | redirect ip2ip Example: Router(conf-voi-serv)# redirect ip2ip | Redirect SIP phone calls to SIP phone calls globally on a gateway using the Cisco IOS voice gateway. |
Step 5 | exit Example: Router(conf-voi-serv)# exit | Exits the current mode. |
Configuring Call Redirect to Support Calls on a Specific VoIP Dial Peer
To configure call redirect to support calls on a specific VoIP dial peer, perform the following steps.
Note
•

To specify IP-to-IP call redirection for a specific VoIP dial peer, configure it on an inbound dial peer in dial-peer configuration mode. The default application on SIP SRST supports IP-to-IP redirection.
•

When IP-to-IP redirection is configured in dial-peer configuration mode, the configuration on the specific inbound dial peer takes precedence over the global configuration entered under voice service configuration.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
dial-peer voice voip 4.
application 5.
redirect ip2ip 6.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | dial-peer voice tag voip Example: Router(config)# dial-peer voice 29 voip | Use this command to enter dial-peer configuration mode. The argument is as follows: • tag—Digits that define a particular dial peer. Range: 1to 2,147,483,647 (enter without commas). |
Step 4 | application application-name Example: Router(config-dial-peer)# application session | Enables a specific application on a dial peer. The argument is as follows: • application-name—Name of the predefined application you wish to enable on the dial peer. For SIP, the default Tcl application (from the Cisco IOS image) is session and can be applied to both VoIP and POTS dial peers. The application must support IP-to-IP redirection |
Step 5 | redirect ip2ip Example: Router(conf-dial-peer)# redirect ip2ip | Redirects SIP phone calls to SIP phone calls on a specific VoIP dial peer using the Cisco IOS voice gateway. |
Step 6 | exit Example: Router(conf-dial-peer)# exit | Exits the current mode. |
Configuring SIP 300 Multiple Choice Messages
This section contains the following information:
•

Sending SIP 300 Multiple Choice Messages
•

Configuring Sending of SIP 300 Multiple Choice Messages
Configuring Sending of SIP 300 Multiple Choice Messages
To send SIP 300 Multiple Choice messages, perform the following steps.
Note 
If multiple routes to a destination exist for a redirected number (multiple dial peers are matched), the SIP gateway sends a 300 Multiple Choice message and the multiple routes in the Contact header are listed. This configuration allows users to choose the order in which the routes appear in the Contact header.
SUMMARY STEPS
1.
enable 2.
configure terminal 3.
voice service voip 4.
sip 5.
redirect contact order 6.
exit DETAILED STEPS
| | Command or Action | Purpose |
Step 1 | enable Example: Router> enable | Enters privileged EXEC mode or any other security level set by a system administrator. Enter your password if prompted. |
Step 2 | configure terminal Example: Router# configure terminal | Enters global configuration mode. |
Step 3 | voice service voip Example: Router(config)# voice service voip | Enters voice-service VoIP configuration mode. |
Step 4 | sip Example: Router(config-voi-serv)# sip | Enters SIP configuration mode. |
Step 5 | redirect contact order [best-match | longest-match] Example: Router(conf-serv-sip)# redirect contact order best-match | Sets the order of contacts in the 300 Multiple Choice Message. Keywords are as follows: • best-match—Use the current system configuration to set the order of contacts. • longest-match—Set the contact order by using the destination pattern longest match first, and then the second longest match, the third longest match, and so on. This is the default. |
Step 6 | exit Example: Router(conf-serv-sip)# exit | Exits the current mode. |
Configuring SIP Implementation Enhancements
Minor underlying or minimally configurable features are described in the following sections:
•

Interaction with Forking Proxies
•

SIP Intra-Gateway Hairpinning
For additional information on SIP implementation enhancements, see "Achieving SIP RFC Compliance" on page 67.
Interaction with Forking Proxies
Call forking enables the terminating gateway to handle multiple requests and the originating gateway to handle multiple provisional responses for the same call. Call forking is required for the deployment of the find me/follow me type of services.
Support for call forking enables the terminating gateway to handle multiple requests and the originating gateway to handle multiple provisional responses for the same call. Interaction with forking proxies applies to gateways acting as a UAC, and takes place when a user is registered to several different locations. When the UAC sends an INVITE message to a proxy, the proxy forks the request and sends it to multiple user agents. The SIP gateway processes multiple 18X responses by treating them as independent transactions under the same call ID. When the relevant dial peers are configured for QoS, the gateway maintains state and initiates RSVP reservations for each of these independent transactions. When it receives an acknowledgment, such as a 200 OK, the gateway accepts the successful acknowledgment and destroys state for all other transactions.
The forking feature sets up RSVP for each transaction only if the dial peers are configured for QoS. If not, the calls proceed as best-effort.
Support for interaction with forking proxies applies only to gateways acting as UACs. It does not apply when the gateway acts as a UAS. In that case, the proxy forks multiple INVITES with the same call ID to the same gateway but with different request URLs.
Also, the forking feature sets up RSVP for each transaction only if the dial peers are configured for QoS. If not, the calls proceed as best-effort.
SIP Intra-Gateway Hairpinning
SIP hairpinning is a call routing capability in which an incoming call on a specific gateway is signaled through the IP network and back out the same gateway. This can be a PSTN call routed into the IP network and back out to the PSTN over the same gateway (see Figure 11).
Figure 11 PSTN Hairpinning Example
Similarly, SIP hairpinning can be a call signaled from a line (for example, a telephone line) to the IP network and back out to a line on the same access gateway (see Figure 12).
Figure 12 Telephone Line Hairpinning Example
With SIP hairpinning, unique gateways for ingress and egress are unnecessary.
SIP supports plain old telephone service (POTS)-to-POTS hairpinning (which means that the call comes in one voice port and is routed out another voice port). It also supports POTS-to-IP call legs and IP-to-POTS call legs. However, it does not support IP-to-IP hairpinning. This means that the SIP gateway cannot take an inbound SIP call and reroute it back to another SIP device using the VoIP dial peers.
Only minimal configuration is required for this feature. To enable hairpinning on the SIP gateway, see the following configuration example for dial peers. Note that:
•

The POTS dial peer must have preference 2 defined, and the VoIP dial peer must have preference 1 defined. This ensures that the call is sent out over IP, not Plain Old Telephone Service (POTS).
•

The session target is the same gateway because the call is being redirected to it.
dial-peer voice 53001 pots
destination-pattern 5300001
dial-peer voice 53002 pots
destination-pattern 5300002
dial-peer voice 530011 voip
destination-pattern 5300001
session target ipv4:10.1.1.41
playout-delay maximum 300
dial-peer voice 530022 voip
destination-pattern 5300002
session target ipv4:10.1.1.41
playout-delay maximum 300
Verifying SIP Gateway Status
To verify SIP gateway status and configuration, perform the following steps as appropriate (commands are listed in alphabetical order).
SUMMARY STEPS
1.
show sip service 2.
show sip-ua register status 3.
show sip-ua statistics 4.
show sip-ua status 5.
show sip-ua timers DETAILED STEPS
Step 1
show sip service Use this command to display the status of SIP call service on a SIP gateway.
The following sample output shows that SIP call service is enabled:
The following sample output shows that SIP call service was shut down with the shutdown command:
SIP service is shut globally
under 'voice service voip'
The following sample output shows that SIP call service was shut down with the call service stop command:
under 'voice service voip', 'sip' submode
The following sample output shows that SIP call service was shut down with the shutdown forced command:
SIP service is forced shut globally
under 'voice service voip'
The following sample output shows that SIP call service was shut down with the call service stop forced command:
SIP service is forced shut
under 'voice service voip', 'sip' submode
Step 2
show sip-ua register status Use this command to display the status of E.164 numbers that a SIP gateway has registered with an external primary SIP registrar.
Router# show sip-ua register status
Line peer expires(sec) registered
Step 3
show sip-ua statistics Use this command to display response, traffic, and retry SIP statistics, including whether call redirection is disabled.
The following sample shows that four registers were sent:
Router# show sip-ua statistics
SIP Response Statistics (Inbound/Outbound)
Forwarded 0/0, Queued 0/0,
OkCancel 0/0, OkOptions 0/0,
OkPrack 0/0, OkPreconditionMet 0/0,
OkSubscribe 0/0, OkNOTIFY 0/0,
OkInfo 0/0, 202Accepted 0/0
Redirection (Inbound only except for MovedTemp(Inbound/Outbound)) :
MultipleChoice 0, MovedPermanently 0,
MovedTemporarily 0/0, UseProxy 0,
BadRequest 0/0, Unauthorized 0/0,
PaymentRequired 0/0, Forbidden 0/0,
NotFound 0/0, MethodNotAllowed 0/0,
NotAcceptable 0/0, ProxyAuthReqd 0/0,
ReqTimeout 0/0, Conflict 0/0, Gone 0/0,
ReqEntityTooLarge 0/0, ReqURITooLarge 0/0,
UnsupportedMediaType 0/0, BadExtension 0/0,
TempNotAvailable 0/0, CallLegNonExistent 0/0,
LoopDetected 0/0, TooManyHops 0/0,
AddrIncomplete 0/0, Ambiguous 0/0,
BusyHere 0/0, RequestCancel 0/0,
NotAcceptableMedia 0/0, BadEvent 0/0,
InternalError 0/0, NotImplemented 0/0,
BadGateway 0/0, ServiceUnavail 0/0,
GatewayTimeout 0/0, BadSipVer 0/0,
BusyEverywhere 0/0, Decline 0/0,
NotExistAnywhere 0/0, NotAcceptable 0/0
RedirectRspMappedToClientErr 0
SIP Total Traffic Statistics (Inbound/Outbound)
Invite 0/0, Ack 0/0, Bye 0/0,
Subscribe 0/0, NOTIFY 0/0,
Invite 0, Bye 0, Cancel 0, Response 0,
Prack 0, Comet 0, Reliable1xx 0, NOTIFY 0
SDP application statistics:
Invalid token order: 0, Invalid param: 0
Not SDP desc: 0, No resource: 0
Last time SIP Statistics were cleared:
The following sample output shows the RedirectResponseMappedToClientError status message. An incremented number indicates that 3xx responses are to be treated as 4xx responses. When call redirection is enabled (default), the RedirectResponseMappedToClientError status message is not incremented.
Router# show sip-ua statistics
SIP Response Statistics (Inbound/Outbound)
Forwarded 0/0, Queued 0/0,
OkCancel 0/0, OkOptions 0/0,
OkPrack 0/0, OkPreconditionMet 0/0,
OKSubscribe 0/0, OkNotify 0/0,
Redirection (Inbound only):
MultipleChoice 0, MovedPermanently 0,
MovedTemporarily 0, UseProxy 0,
BadRequest 0/0, Unauthorized 0/0,
PaymentRequired 0/0, Forbidden 0/0,
NotFound 0/0, MethodNotAllowed 0/0,
NotAcceptable 0/0, ProxyAuthReqd 0/0,
ReqTimeout 0/0, Conflict 0/0, Gone 0/0,
ReqEntityTooLarge 0/0, ReqURITooLarge 0/0,
UnsupportedMediaType 0/0, BadExtension 0/0,
TempNotAvailable 0/0, CallLegNonExistent 0/0,
LoopDetected 0/0, TooManyHops 0/0,
AddrIncomplete 0/0, Ambiguous 0/0,
BusyHere 0/0, RequestCancel 0/0
NotAcceptableMedia 0/0, BadEvent 0/0
InternalError 0/0, NotImplemented 0/0,
BadGateway 0/0, ServiceUnavail 0/0,
GatewayTimeout 0/0, BadSipVer 0/0,
BusyEverywhere 0/0, Decline 0/0,
NotExistAnywhere 0/0, NotAcceptable 0/0
RedirectResponseMappedToClientError 1,
SIP Total Traffic Statistics (Inbound/Outbound)
Invite 0/0, Ack 0/0, Bye 0/0,
Subscribe 0/0, Notify 0/0,
Invite 0, Bye 0, Cancel 0, Response 0,
Prack 0, Comet 0, Reliable1xx 0, Notify 0
SDP application statistics:
Invalid token order: 0, Invalid param: 0
Not SDP desc: 0, No resource: 0
Step 4
show sip-ua status Use this command to display status for the SIP user agent (UA), including whether call redirection is enabled or disabled.
Router# show sip-ua status
SIP User Agent for UDP : ENABLED
SIP User Agent for TCP : ENABLED
SIP User Agent bind status(signaling): DISABLED
SIP User Agent bind status(media): DISABLED
SIP DNS SRV version: 1 (rfc 2052)
Redirection (3xx) message handling: ENABLED
Step 5
show sip-ua timers Use this command to display the current settings for the SIP user-agent (UA) timers.
The following sample output shows the waiting time before a register request is sent—that is, the value that is set with the timers register command:
Router# show sip-ua timers
SIP UA Timer Values (millisecs)
trying 500, expires 180000, connect 500, disconnect 500
comet 500, prack 500, rel1xx 500, notify 500
General Troubleshooting Tips
Note 
For more information on troubleshooting, see the following references:
•

Cisco IOS Voice Troubleshooting and Monitoring Guide
•

Cisco IOS Debug Command Reference, Release 12.3T
•

Troubleshooting and Debugging VoIP Call Basics
•

Voice Gateway Error Decoder for Cisco IOS
•

VoIP Debug Commands
Note 
Commands are listed in alphabetical order.
•

Make sure that VoIP is working.
•

Make sure that you can make a voice call.
•

Verify that SIP-supported codecs are used.
Support for codecs varies on different platforms; use the
codec ? command to determine the codecs available on a specific platform.
•

Use the
debug aaa authentication command to display high-level diagnostics related to AAA logins.
•

Use the
debug asnl events command to verify that the SIP subscription server is up. The output displays a pending message if, for example, the client is unsuccessful in communicating with the server.
•

Use the
debug call fallback family of commands to display details of VoIP call fallback.
•

Use the
debug cch323 family of commands to provide debugging output for various components within an H.323 subsystem.
•

Use the
debug ccsip family of commands for general SIP debugging, including viewing direction-attribute settings and port and network address-translation traces. Use any of the following related commands:
–
debug ccsip all—Enables all SIP-related debugging
–
debug ccsip calls—Enables tracing of all SIP service-provider interface (SPI) calls
–
debug ccsip error—Enables tracing of SIP SPI errors
–
debug ccsip events—Enables tracing of all SIP SPI events
–
debug ccsip info—Enables tracing of general SIP SPI information, including verification that call redirection is disabled
–
debug ccsip media—Enables tracing of SIP media streams
–
debug ccsip messages—Enables all SIP SPI message tracing, such as those that are exchanged between the SIP user-agent client (UAC) and the access server
–
debug ccsip preauth—Enables diagnostic reporting of authentication, authorization, and accounting (AAA) preauthentication for SIP calls
–
debug ccsip states—Enables tracing of all SIP SPI state tracing
–
debug ccsip transport—Enables tracing of the SIP transport handler and the TCP or User Datagram Protocol (UDP) process
•

Use the
debug isdn q931 command to display information about call setup and teardown of ISDN network connections (layer 3) between the local router (user side) and the network.
•

Use the
debug kpml command to enable debug tracing of KeyPad Markup Language (KPML) parser and builder errors.
•

Use the
debug radius command to enable debug tracing of RADIUS attributes.
•

Use the
debug rpms-proc preauth command to enable debug tracing on the RPMS process for H.323 calls, SIP calls, or both H.323 and SIP calls.
•

Use the
debug rtr trace command to trace the execution of an SAA operation.
•

Use the
debug voip family of commands, including the following:
–
debug voip ccapi protoheaders—Displays messages sent between the originating and terminating gateways. If no headers are being received by the terminating gateway, verify that the
header-passing command is enabled on the originating gateway.
–
debug voip ivr script—Displays any errors that might occur when the Tcl script is run
–
debug voip rtp session named-event 101—Displays information important to DTMF-relay debugging, if you are using codec types g726r16 or g726r24. Be sure to append the argument
101 to the
command to prevent the console screen from flooding with messages and all calls from failing.
Sample output for some of these commands follows:
Sample Output for the debug ccsip events Command
•

The example shows how the Proxy-Authorization header is broken down into a decoded username and password.
Router# debug ccsip events
CCSIP SPI: SIP Call Events tracing is enabled
21:03:21: sippmh_parse_proxy_auth: Challenge is 'Basic'.
21:03:21: sippmh_parse_proxy_auth: Base64 user-pass string is
'MTIzNDU2Nzg5MDEyMzQ1Njou'.
21:03:21: sip_process_proxy_auth: Decoded user-pass string is '1234567890123456:.'.
21:03:21: sip_process_proxy_auth: Username is '1234567890123456'.
21:03:21: sip_process_proxy_auth: Pass is '.'.
21:03:21: sipSPIAddBillingInfoToCcb: sipCallId for billing records =
10872472-173611CC-81E9C73D-F836C2B6@172.18.192.19421:03:21: ****Adding to UAS Request
table
Sample Output for the debug ccsip info Command
This example shows only the portion of the debug output that shows that call redirection is disabled. When call redirection is enabled (default), there are no debug line changes.
00:20:32: HandleUdpSocketReads :Msg enqueued for SPI with IPaddr: 172.18.207.10
00:20:32: CCSIP-SPI-CONTROL: act_sentinvite_new_message
00:20:32: CCSIP-SPI-CONTROL: sipSPICheckResponse
00:20:32: sip_stats_status_code
00:20:32: ccsip_get_code_class: !!Call Redirection feature is disabled on the GW
00:20:32: ccsip_map_call_redirect_responses: !!Mapping 302 response to 480
00:20:32: Roundtrip delay 4 milliseconds for method INVITE
Configuration Examples for Basic SIP Configuration
This section provides the following configuration examples:
•

SIP Register Support: Example
•

SIP Redirect Processing Enhancement: Examples
•

SIP 300 Multiple Choice Messages: Example
SIP Register Support: Example
Current configuration : 3394 bytes
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
redirect contact order best-match
network 192.168.0.0 255.255.255.0
option 150 ip 192.168.0.1
default-router 192.168.0.1
voice call carrier capacity active
codec preference 2 g711ulaw
no voice hpi capture buffer
no voice hpi capture destination
fax interface-type fax-mail
mta receive maximum-recipients 0
ip address 10.8.17.22 255.255.0.0
interface FastEthernet0/0
ip address 192.168.0.1 255.255.255.0
h323-gateway voip interface
h323-gateway voip id vespa2 ipaddr 10.8.15.4 1718
ip default-gateway 10.8.0.1
ip route 0.0.0.0 0.0.0.0 10.8.0.1
tftp-server flash:SEPDEFAULT.cnf
tftp-server flash:P005B302.bin
call application global default.new
destination-pattern [12]...
session target ipv4:10.8.17.42
registrar dns:myhost3.example.com expires 3600
registrar ipv4:10.8.17.40 expires 3600 secondary
SIP Redirect Processing Enhancement: Examples
This section provides configuration examples to match the identified configuration tasks in the previous sections.
•

Call Redirection Disabled
•

Call Redirection Enabled
•

Call Redirection Using IP-to-IP Redirection
•

SIP 300 Multiple Choice Messages: Example
Note 
IP addresses and hostnames in examples are fictitious.
Call Redirection Disabled
This example shows that call redirection is disabled on the gateway.
Router# show running-config
Building configuration...
Current configuration : 2791 bytes
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
interface FastEthernet2/0
ip address 172.18.200.24 255.255.255.0
ip rsvp bandwidth 7500 7500
no supervisory disconnect lcfo
destination-pattern 8183821111
destination-pattern 7173721111
session target ipv4:172.18.200.36
destination-pattern 6163621111
session target ipv4:172.18.200.33
Call Redirection Enabled
This example shows that call redirection is enabled on the gateway (the default). WHen call redirection is enabled, the output shows no redirection.
Router# show running-config
Building configuration...
Current configuration : 2791 bytes
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service udp-small-servers
interface FastEthernet2/0
ip address 172.18.200.24 255.255.255.0
ip rsvp bandwidth 7500 7500
no supervisory disconnect lcfo
destination-pattern 8183821111
destination-pattern 7173721111
session target ipv4:172.18.200.36
destination-pattern 6163621111
session target ipv4:172.18.200.33
Call Redirection Using IP-to-IP Redirection
This example shows that redirection was set globally on the router.
Current configuration : 3394 bytes
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
redirect contact order best-match
network 192.168.0.0 255.255.255.0
option 150 ip 192.168.0.1
default-router 192.168.0.1
voice call carrier capacity active
codec preference 2 g711ulaw
no voice hpi capture buffer
no voice hpi capture destination
fax interface-type fax-mail
mta receive maximum-recipients 0
ip address 10.8.17.22 255.255.0.0
interface FastEthernet0/0
ip address 192.168.0.1 255.255.255.0
h323-gateway voip interface
h323-gateway voip id vespa2 ipaddr 10.8.15.4 1718
ip default-gateway 10.8.0.1
ip route 0.0.0.0 0.0.0.0 10.8.0.1
tftp-server flash:SEPDEFAULT.cnf
tftp-server flash:P005B302.bin
call application global default.new
destination-pattern [12]...
session target ipv4:10.8.17.42
registrar dns:myhost3.example.com expires 3600
registrar ipv4:10.8.17.40 expires 3600 secondary
SIP 300 Multiple Choice Messages: Example
This section provides a configuration example showing redirect contact order set to best match.
Current configuration : 3394 bytes
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
redirect contact order best-match
network 192.168.0.0 255.255.255.0
option 150 ip 192.168.0.1
default-router 192.168.0.1
voice call carrier capacity active
codec preference 2 g711ulaw
no voice hpi capture buffer
no voice hpi capture destination
fax interface-type fax-mail
mta receive maximum-recipients 0
ip address 10.8.17.22 255.255.0.0
interface FastEthernet0/0
ip address 192.168.0.1 255.255.255.0
h323-gateway voip interface
h323-gateway voip id vespa2 ipaddr 10.8.15.4 1718
ip default-gateway 10.8.0.1
ip route 0.0.0.0 0.0.0.0 10.8.0.1
tftp-server flash:SEPDEFAULT.cnf
tftp-server flash:P005B302.bin
call application global default.new
destination-pattern [12]...
session target ipv4:10.8.17.42
registrar dns:myhost3.example.com expires 3600
registrar ipv4:10.8.17.40 expires 3600 secondary
end
Additional References
•
"SIP Features Roadmap" on page 1—Describes how to access Cisco Feature
Navigator; also lists and describes, by Cisco IOS release, SIP features
for that release.