HNT Configuration

To configure a SIP interface on the Oracle® Enterprise Session Border Controller (E-SBC):

1. In Superuser mode, type configure terminal and press Enter.

   ORACLE# configure terminal

2. Type session-router and press Enter to access the system-level configuration elements.

   ORACLE(configure)# session-router

3. Type sip-interface and press Enter. The system prompt changes to let you know that you can begin configuring individual parameters.

   ORACLE(session-router)# sip-interface
   ORACLE(sip-interface)#

   From this point, you can configure sip-interface parameters. To view all sip-interface parameters, enter a ? at the system prompt.

4. nat-traversal—Define the type of HNT enabled for SIP. The default value is none. Available values include:

   • none—Disables the HNT feature for SIP (default value)

   • rport—SIP HNT function only applies to endpoints that include the rport parameter in the Via header and the sent-by of the topmost VIA matches the Contact-URI host address, both of which must be different from the received Layer 3 address.

   • always—SIP HNT applies to requests when the sent-by of the topmost VIA matches the Contact-URI host address, both of which must be different from the received Layer 3 address. (Even when the rport parameter is not present.)

5. nat-interval—Set the expiration time in seconds for the E-SBC’s cached registration entry for an HNT endpoint. The default value is 30. The valid range is:

   • Minimum—0

   • Maximum—999999999

     Acme Packet recommends setting the NAT interval to one-third of the NAT binding lifetime. A NAT binding lifetime is the network connection inactivity timeout. The value is configured (or hardwired) in the NAT device (firewall). This timer is used to prevent the NAT device from keeping an unused port open.

6. registration-caching—Enable for use with all UAs, not just those that are behind NATs. By default, this field is set to disabled. If enabled, the E-SBC caches the Contact header in the UA’s REGISTER request when it is addressed to one of the following:

   • E-SBC

   • registrar domain value

   • registrar host value

     The E-SBC then generates a Contact header with the E-SBC’s address as the host part of the URI and sends the REGISTER to the destination defined by the registrar host value.

     Whether or not SIP HNT functionality is enabled affects the value of the user part of the URI sent in the Contact header:

   • enabled—The E-SBC takes the user part of the URI in the From header of the request and appends a cookie to make the user unique. A cookie is information that the server stores on the client side of a client-server communication so that the information can be used in the future.

   • disabled—The user part of the Contact header is taken from the URI in the From header and no cookie is appended. This is the default behavior of the Oracle® Enterprise Session Border Controller.

     When the registrar receives a request that matches the address-of-record (the To header in the REGISTER message), it sends the matching request to the E-SBC, which is the Contact address. Then, the v forwards the request to the Contact-URI it cached from the original REGISTER message.

7. min-reg-expire—Set the time in seconds for the SIP interface. The value you enter here sets the minimum registration expiration time in seconds for HNT registration caching. The default value is 300. The valid range is:

   • Minimum—1

   • Maximum—999999999

     This value defines the minimum expiration value the E-SBC places in each REGISTER message it sends to the real registrar. In HNT, the E-SBC caches the registration after receiving a response from the real registrar and sets the expiration time to the NAT interval value.

     Some UAs might change the registration expiration value they use in subsequent requests to the value specified in this field. This change causes the E-SBC to send frequent registrations on to the real registrar.

8. registration-interval—Set the E-SBC’s cached registration entry interval for a non-HNT endpoint. Enter the expiration time in seconds that you want the E-SBC to use in the REGISTER response message sent back to the UA. The UA then refreshes its registration by sending another REGISTER message before that time expires. The default value is 3600. The valid range is:

   • Minimum—1

     A registration interval of zero causes the E-SBC to pass back the expiration time set by and returned in the registration response from the registrar.

   • Maximum—999999999

     If the expiration time you set is less than the expiration time set by and returned from the real registrar, the E-SBC responds to the refresh request directly rather than forwarding it to the registrar.

     Note:

     With registration caching, there is no NAT; therefore, a short registration interval causes the UA to send excess REGISTER messages.

     Although the registration interval applies to non-HNT registration cache entries, and the loosely related NAT interval applies to HNT registration cache entries, you can use the two in combination. Using a combination of the two means you can implement HNT and non-HNT architectures on the same E-SBC. You can then define a longer interval time in the registration interval field to reduce the network traffic and load caused by excess REGISTER messages because there is no NAT binding to maintain.

9. route-to-registrar—Enable routing to the registrar to send all requests that match a cached registration to the destination defined for the registrar host; used when the Request-URI matches the registrar host value or the registrar domain value, not the SBC’s address. Because the registrar host is the real registrar, it should send the requests back to the E-SBC with the E-SBC’s address in the Request-URI. The default value is disabled. The valid values are:

   • enabled | disabled

     For example, you should enable routing to the registrar if your network uses a E-SBC and needs requests to go through its service proxy, which is defined in the registrar host field.