Configuring the SBC to Hide Session Updates

You configure the SBC to hide session updates by configuring hsu-policy within the session-router element, then applying the policy to a sip-interface, realm-config, or session-agent, following that precedence.

1. Access the hsu-policy configuration element:

   ORACLE# configure terminal
   ORACLE(configure)# session-router
   ORACLE(session-router)# hsu-policy
   ORACLE(hsu-policy)#

2. Configure the following parameters:
   • name: The name for the policy, to use when applying it to an interface, realm, or session agent.
   • The following parameters control when to hide session updates. They are all enabled by default.
     • hsu-reinvite-offerless: When enabled, hide offerless reINVITEs.
     • hsu-reinvite-hold-resume: When enabled, hide hold and resume reINVITEs.
     • hsu-reinvite-sdp-except-hold-resume: When enabled, hide all reINVITEs except hold and resume requests.
     • hsu-update-offerless: When enabled, hide offerless UPDATEs.
     • hsu-update-hold-resume: When enabled, hide hold and resume UPDATEs.
     • hsu-update-sdp-except-hold-resume: When enabled, hide all UPDATEs except hold and resume requests.
   • The following parameters control additional behavior. They are all disabled or unset by default.
     • hsu-headers: When set, if any of the specified headers are different in the reINVITE or UPDATE than the original INVITE, do not hide the UPDATE or reINVITE. Send it on to the opposite side without considering any other hsu-policy configurations.

       You can configure a maximum of three comma-separated headers. Supported headers are:

       • P-Asserted-Identity
       • P-Preferred-Identity
       • Remote-Party-ID
       • Privacy
       • Diversion
       • History-Info
     • hsu-force-xcode: When enabled, the SBC forces transcoding with the top codec received in the new offer. When disabled, the SBC tries to negotiate a common codec before transcoding.

       This parameter applies to audio calls only.

     • hsu-force-ptime: When enabled, when ptimes are different, the SBC hides session updates and forces transrating. When disabled, the SBC tries to negotiate a common ptime before transrating.
     • hsu-silent-rtp-on-hold: When enabled, when the call is on hold and the SBC is hiding session updates, if there is no RTP flow from the side that put the call on hold, the SBC sends blank RTP packets toward the opposite side. This uses DSP resources.

       This parameter applies to audio calls only.

3. Apply the hsu-policy to an interface, realm, or session agent. For example, to apply an hsu-policy called MyHSUPolicy to an interface:

   ORACLE(configure)# session-router
   ORACLE(session-router)# sip-interface
   ORACLE(sip-interface)# hsu-policy MyHSUPolicy

4. Use done, verify-config, and activate-config to complete your configuration.

   This configuration supports real-time configuration. You do not have to reboot.

Note:

If you have already configured and applied an hsu-policy, and you change those configurations, or apply an hsu-policy to a new interface, realm, or session agent, the changes will not apply to ongoing calls. They will apply to subsequent calls.