- Cisco Unified Border Element SIP Support
- SIP Core SIP Technology Enhancements
- Reporting End-of-Call Statistics in SIP BYE Message
- Configurable Hostname in Locally Generated SIP Headers
- SIP Parameter Modification
- SIP Session Timer Support
- SIP-to-SIP Basic Functionality for Session Border Controller
- SIP-to-SIP Supplementary Services for Session Border Controller
- Session Refresh with Reinvites
- Configuring Cisco UBE Out-of-dialog OPTIONS Ping for Specified SIP Servers or Endpoints
- Configuring an Error Response Code upon an Out-of-Dialog OPTIONS Ping Failure
- SIP INFO Method for DTMF Tone Generation
- SIP Enhanced 180 Provisional Response Handling
- Configuring SIP 181 Call is Being Forwarded Message
- Expires Timer Reset on Receiving or Sending SIP 183 Message
- SIP UPDATE Message per RFC 3311
- Support for PAID PPID Privacy PCPID and PAURI Headers on the Cisco Unified Border Element
- Configurable Pass-through of SIP INVITE Parameters
- Conditional Header Manipulation of SIP Headers
- Transparent Tunneling of QSIG and Q.931
- SIP Diversion Header Enhancements
- SIP History INFO
- SIP Ability to Send a SIP Registration Message on a Border Element
- Configurable SIP Parameters via DHCP
- Multiple Registrars on SIP Trunks
- Additional References
- Glossary
- Finding Feature Information
- Prerequisites for Configurable SIP Parameters via DHCP
- Restrictions for Configurable SIP Parameters via DHCP
- Information About Configurable SIP Parameters via DHCP
- How to Configure SIP Parameters via DHCP
- Configuring the DHCP Client
- Configuring the DHCP Client Example
- Enabling the SIP Configuration
- Enabling the SIP Configuration Example
- Troubleshooting Tips
- Configuring a SIP Outbound Proxy Server
- Configuring a SIP Outbound Proxy Server in Voice Service VoIP Configuration Mode
- Configuring a SIP Outbound Proxy Server in Voice Service VoIP Configuration Mode Example
- Configuring a SIP Outbound Proxy Server and Session Target in Dial Peer Configuration Mode
- Configuring a SIP Outbound Proxy Server in Dial Peer Configuration Mode Example
- Feature Information for Configurable SIP Parameters via DHCP
Configurable SIP Parameters via DHCP
The Configurable SIP Parameters via DHCP feature allows a Dynamic Host Configuration Protocol (DHCP) server to provide Session Initiation Protocol (SIP) parameters via a DHCP client. These parameters are used for user registration and call routing.
The DHCP server returns the SIP Parameters via DHCP options 120 and 125. These options are used to specify the SIP user registration and call routing information. The SIP parameters returned are the SIP server address via Option 120, and vendor-specific information such as the pilot, contract or primary number, an additional range of secondary numbers, and the SIP domain name via Option 125.
In the event of changes to the SIP parameter values, this feature also allows a DHCP message called DHCPFORCERENEW to reset or apply a new set of values.
The SIP parameters provisioned by DHCP are stored, so that on reboot they can be reused.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Configurable SIP Parameters via DHCP
- A DHCP interface has to be associated with SIP before configurable SIP parameters via DHCP can be enabled.
Cisco Unified Border Element
- Cisco IOS Release 12.4(22)YB or a later release must be installed and running on your Cisco Unified Border Element.
Cisco Unified Border Element (Enterprise)
- Cisco IOS XE Release <TBD> or a later release must be installed and running on your Cisco ASR 1000 Series Router.
Restrictions for Configurable SIP Parameters via DHCP
- DHCP Option 120 is the standard DHCP option (RFC3361) to get a SIP server address, and this can be used by any vendor DHCP server. Only one address is supported, which is in the IPv4 address format. Multiple IPv4 address entries are not supported. Also, there is no support for a DNS name in this or for any port number given behind the IPv4 address.
- DHCP Option 125 (RFC 3925) provides vendor-specific information and its interpretation is associated with the enterprise identity. The primary and secondary phone numbers and domain are obtained using Option 125, which is vendor-specific. As long as other customers use the same format as in the Next Generation Network (NGN) DHCP specification, they can use this feature.
- A primary or contract number is required in suboption 202 of DHCP Option 125. There can be only one instance of the primary number and not multiple instances.
- Multiple secondary or numbers in suboption 203 of DHCP Option 125 are supported. Up to five numbers are accepted and the rest ignored. Also, they have to follow the contract number in the DHCP packet data.
- Authentication is not supported for REGISTER and INVITE messages sent from a Cisco Unified Border Element that uses DHCP provisioning
- The DHCP provisioning of SIP Parameters is supported only over one DHCP interface.
- The DHCP option is available only to be configured for the primary registrar. It will not be available for a secondary registrar.
Information About Configurable SIP Parameters via DHCP
To perform basic Configurable SIP Parameters via DHCP configuration tasks, you should understand the following concepts:
Cisco Unified Border Element Support for Configurable SIP Parameters via DHCP
The Cisco Unified Border Element provides the support for the DHCP provisioning of the SIP parameters.
The NGN is modeled using SIP as a VoIP protocol. In order to connect to NGN, the User to Network Interface (UNI) specification is used. Cisco TelePresence Systems (CTS), consisting of an IP Phone, a codec, and Cisco Unified Communications Manager, are required to internetwork over the NGN for point-to-point and point-to-multipoint video calls. Because Cisco Unified Communications Manager does not provide a UNI interface, there has to be an entity to provide the UNI interface. The Cisco Unified Border Element provides the UNI interface and has several advantages such as demarcation, delayed offer to early offer, and registration.
The figure below shows the Cisco Unified Border Element providing the UNI interface for the NGN.
| Figure 1 | Cisco NGN with Cisco Unified Border Element providing UNI interface |
DHCP to Provision SIP Server, Domain Name, and Phone Number
NGN requires Cisco Unified Border Element to support DHCP (RFC 2131 and RFC 2132) to provision the following:
DHCP-SIP Call Flow
The following scenario shows the DHCP messages involved in provisioning information such as the IP address for UNI interface, and SIP parameters including the SIP server address, phone number, and domain name, along with how SIP messages use the provisioned information.
The figure below shows the DHCP and SIP messages involved in obtaining the SIP parameters and using them for REGISTER and INVITE.
| Figure 2 | DHCP-SIP Call Flow |
DHCP Message Details
The DHCP call flow involved in obtaining Cisco Unified Border Element provision information, including the IP address for UNI interface and SIP information such as phone number, domain, and SIP server, is shown in the figure below.
| Figure 3 | DHCP Message Details |
The DHCP messages involved in provisioning the SIP parameters are described in Steps 1 to 6.
- F1: The Cisco Unified Border Element DHCP client sends a DHCPDISCOVER message to find the available NGN DHCP servers on the network and obtain a valid IPv4 address. The Cisco Unified Border Element DHCP client identity (computer name) and MAC address are included in this message.
- F2: The Cisco Unified Border Element DHCP client receives a DHCPOFFER message from each available NGN DHCP server. The DHCPOFFER message includes the offered DHCP server's IPv4 address, the DHCP client's MAC address, and other configuration parameters.
- F3: The Cisco Unified Border Element DHCP client selects an NGN DHCP server and its IPv4 address configuration from the DHCPOFFER messages it receives, and sends a DHCPREQUEST message requesting its usage. Note that this is where Cisco Unified Border Element requests SIP server information via DHCP Option 120 and vendor- identifying information via DHCP Option 125.
- F4: The chosen NGN DHCP server assigns its IPv4 address configuration to the Cisco Unified Border Element DHCP client by sending a DHCPACK message to it. The Cisco Unified Border Element DHCP client receives the DHCPACK message. This is where the SIP server address, phone number and domain name information are received via DHCP options 120 and 125. The Cisco Unified Border Element will use the information for registering the phone number and routing INVITE messages to the given SIP server.
- F5: When NGN has a change of information or additional information (such as changing SIP server address from 1.1.1.1 to 2.2.2.2) for assigning to Cisco Unified Border Element, the DHCP server initiates DHCPFORCERENEW to the Cisco Unified Border Element. If the authentication is successful, the Cisco Unified Border Element DHCP client accepts the DHCPFORCERENEW and moves to the next stage of sending DHCPREQUEST. Otherwise DHCPFORCERENEW is ignored and the current information is retained and used.
- F6 and F7: In response to DHCPFORCERENEW, similar to steps F3 and F4, the Cisco Unified Border Element requests DHCP Options 120 and 125. Upon getting the response, SIP will apply these parameters if they are different by sending an UN-REGISTER message for the previous phone number and a REGISTER message for the new number. Similarly, a new domain and SIP server address will be used. If the returned information is the same as the current set, it is ignored and hence registration and call routing remains the same.
How to Configure SIP Parameters via DHCP
- Configuring the DHCP Client
- Configuring the DHCP Client Example
- Enabling the SIP Configuration
- Enabling the SIP Configuration Example
- Troubleshooting Tips
- Configuring a SIP Outbound Proxy Server
- Configuring a SIP Outbound Proxy Server in Voice Service VoIP Configuration Mode
- Configuring a SIP Outbound Proxy Server in Voice Service VoIP Configuration Mode Example
- Configuring a SIP Outbound Proxy Server and Session Target in Dial Peer Configuration Mode
- Configuring a SIP Outbound Proxy Server in Dial Peer Configuration Mode Example
Configuring the DHCP Client
To receive the SIP configuration parameters the Cisco Unified Border Element has to act as a DHCP client. This is because in the NGN network, a DHCP server pushes the configuration to a DHCP client. Thus the Cisco Unified Border Element must be configured as a DHCP client.
Perform this task to configure the DHCP client.
You must configure the ip dhcp client commands before entering the ip address dhcp command on an interface to ensure that the DHCPDISCOVER messages that are generated contain the correct option values. The ip dhcp clientcommands are checked only when an IP address is acquired from DHCP. If any of the ip dhcp client commands are entered after an IP address has been acquired from DHCP, the DHCPDISCOVER messages' correct options will not be present or take effect until the next time the router acquires an IP address from DHCP. This means that the new configuration will only take effect after either the ip address dhcp command or the release dhcp and renew dhcp EXEC commands have been configured.
DETAILED STEPS
Configuring the DHCP Client Example
The following is an example of how to enable the DHCP client:
Router> enable Router# configure terminal Router(config)# interface gigabitethernet 1/1 Router(config-if)# ip dhcp client request sip-server-address Router(config-if)# ip dhcp client request vendor-identifying-specific Router(config-if)# ip address dhcp Router(config-if)# exit
Enabling the SIP Configuration
Enabling the SIP configuration allows the Cisco Unified Border Element to use the SIP parameters received via DHCP for user registration and call routing. Perform this task to enable the SIP configuration.
The dhcp interface command has to be entered to declare the interface before the registrar and credential commands are entered.
DETAILED STEPS
Enabling the SIP Configuration Example
The following is an example of how to enable the SIP configuration:
Router> enable Router# configure terminal Router(config)# interface gigabitethernet 1/0 Router(config-if)# sip-ua Router(sip-ua)# dhcp interface gigabitethernet 1/0 Router(sip-ua)# registrar dhcp expires 90 random-contact refresh-ratio 90 Router(sip-ua)# credentials dhcp password cisco realm cisco.com Router(sip-ua)# exit
Troubleshooting Tips
To display information on DHCP and SIP interaction when SIP parameters are provisioned by DHCP, use the debug ccsip dhcp command in privileged EXEC mode.
Configuring a SIP Outbound Proxy Server
An outbound-proxy configuration sets the Layer 3 address (IP address) for any outbound REGISTER and INVITE SIP messages. The SIP server can be configured as an outbound proxy server in voice service SIP configuration mode or dial peer configuration mode. When enabled in voice service SIP configuration mode, all the REGISTER and INVITE messages are forwarded to the configured outbound proxy server. When enabled in dial-peer configuration mode, only the messages hitting the defined dial-peer will be forwarded to the configured outbound proxy server.
The configuration tasks in each mode are presented in the following sections:
Perform either of these tasks to configure the SIP server as a SIP outbound proxy server.
Configuring a SIP Outbound Proxy Server in Voice Service VoIP Configuration Mode
Perform this task to configure the SIP server as a SIP outbound proxy server in voice service SIP configuration mode.
DETAILED STEPS
Configuring a SIP Outbound Proxy Server in Voice Service VoIP Configuration Mode Example
The following is an example of how to configure a SIP outbound proxy in voice service SIP configuration mode:
Router> enable Router# configure terminal Router(config)# voice service voip Router(config-voi-srv)# sip Router(conf-serv-sip)# outbound-proxy dhcp Router(config-serv-if)# exit
Configuring a SIP Outbound Proxy Server and Session Target in Dial Peer Configuration Mode
Perform this task to configure the SIP server as a SIP outbound proxy server in dial peer configuration mode.
 Note |
SIP must be configured on the dial pier before DHCP is configured. Therefore the session protocol sipv2 command must be executed before the session target dhcp command. DHCP is supported only with SIP configured on the dial peer. > |
DETAILED STEPS
Configuring a SIP Outbound Proxy Server in Dial Peer Configuration Mode Example
The following is an example of how to configure a SIP outbound proxy in dial peer configuration mode:
Router> enable Router# configure terminal Router(config)# dial-peer voice 11 voip Router(config-dial-peer)# session protocol sipv2 Router(config-dial-peer)# voice-class sip outbound-proxy dhcp Router(config-dial-peer)# session target dhcp Router(config-dial-peer)# exit
Feature Information for Configurable SIP Parameters via DHCP
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature History Table for the ISR.
| Table 1 | Feature Information for Configurable SIP Parameters via DHCP |
| Feature Name |
Releases |
Feature Information |
|---|---|---|
| Configurable SIP Parameters via DHCP |
12.4(22)YB 15.0(1)M |
The Configurable SIP Parameters via DHCP feature introduces the configuring of SIP parameters via DHCP. The following commands were introduced or modified: credentials (sip-ua), debug ccsip dhcp, dhcp interface, ip dhcp-client forcerenew, outbound-proxy, registrar, session target (VoIP dial peer), show sip dhcp, voice-class sip outbound-proxy. |
Feature History Table for the ASR.
| Table 2 | Feature Information for Configurable SIP Parameters via DHCP |
| Feature Name |
Releases |
Feature Information |
|---|---|---|
| Configurable SIP Parameters via DHCP |
IOS XE Release <TBD> |
The Configurable SIP Parameters via DHCP feature introduces the configuring of SIP parameters via DHCP. The following commands were introduced or modified: credentials (sip-ua), debug ccsip dhcp, dhcp interface, ip dhcp-client forcerenew, outbound-proxy, registrar, session target (VoIP dial peer), show sip dhcp, voice-class sip outbound-proxy. |
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
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