Signaling - SIP Sig Controls

The maximum PDU size that the SBC recognizes.

The options are:

• pdusize2kb
• pdusize3kb
• pdusize6kb
• pdusize15kb (default)
• pdusize32kb
• pdusize60kb

Specify the flag to allow the SBC to sends a Redirecting Number Information Element (RNIE) in the egress leg of a call per RFC 3398 when the Request URI and the To header differ.

• Disabled
• Enabled (default)

Enable this flag to support the multiple contacts per Address Of Record (AoR).

• Disabled – Only a single contact per AoR is supported.
• Enabled (default) – The SBC maintains different Registration Control Blocks (RCBs) for each new registration and verifies the source IP address and port during RCB lookup.

The SBC supports validating the source IP address and the port even if Multiple Contacts Per Aor is Disabled. The SBC also supports locating the RCB using the AoR to perform additional validation on the source IP address and port if you set the option Require Registrationto "required" or "required-non-priority". This is applicable for both calls and out-of-dialog (OOD) requests that are originated from the IAD.

For refreshing registration that originates from a different IP/port, the SBC forwards the request to the registrar and moves the state to "UPDATING". Validate any calls or OOD requests that originate from the IAD while the RCB is in updating state, using the previously authenticated IP/port.

When Multiple Contacts Per Aor is Enabled, the SBC maintains different RCBs for each new registration. The SBC considers a new registration when the source IP/port of the REGISTER request is different from an earlier registration for the same AoR. Any of the registered UEs may initiate a communication on behalf of the AoR. The SBC fetches the corresponding RCB based on the source IP/port of the UE.

NOTE: Even though the default value of Multiple Contacts Per Aor is Enabled, during an upgrade, the value can be either "Enabled" or "Disabled".

Refer to Multiple Contacts per AoR for additional details.

Enable this option to allow the SBC   to send the Contact header as an asterisk (*) in de-REGISTER messages if Multiple Contacts Per Aor is Disabled.

• Disabled
• Enabled (default)

Specify the number of seconds for the SBC to wait for the Offer-Answer handshake to complete before timing out.    

Once configured, the SBC uses this value for all subsequent calls.

For backward compatibility, set the Offer Answer Timer to its default value for SIP signaling gateway.

Note:

The Offer Answer Timer goes beyond transaction timeout value only for re-INVITE  transactions. For Media Resource Function timer (MRF) calls, if the Offer Answer Timer value has a value more than MRF timer value,  which is currently hard coded to 72 seconds , the call disconnects on MRF timer timeout, irrespective of the Offer Answer Timer timer value.

Enable this flag to control the sending of 503 message during a switchover.

• Disabled  – The SBC drops the request  with no 503 message sent for INVITEs. 
• Enabled  (default) – The SBC sends the 503 messages during a switchover.

NOTE: The Retry-After tag is set to 60 seconds in the 503 sent.

 Enable this flag to control whether the SBC removes the enumdi (ENUM dip indicator) parameter from the egress Request-URI that the SBC inserts when the PSX does an ENUM query. The options are:

Disabled (default) - The SBC includes the enumdi parameter in the egress Request-URI when the PSX does an ENUM query.

Enabled - The SBC does not include the enumdi parameter in the egress Request-URI even though the PSX does an ENUM query.

Note: This feature is only applicable for TCP/TLS transports.

After an SBC switchover, the first REGISTER request sent by the UE is not matched to an existing TCP connection on the newly-active SBC. This will eventually lead the UE to become aware of the lost TCP connection, and the UE will then establish a new TCP connection and send an initial REGISTER request using the same IP address but with a different port compared to the TCP connection established before the switchover as the selection of client source port for a new TCP connection is usually ephemeral.

The SBC relays the initial REGISTER request sent by the UE to the Registrar as it creates a new AoR. Thus, the Registrar receives a high rate of REGISTER requests after an SBC switchover.

Enable this flag for the SBC to search for and validate that the initial REGISTER over the new TCP/TLS connection matches the synchronized RCB after a switchover. The SBC checks that the source IP address used for the new connection matches the old one regardless of the port value (It needs to update the port value and only for the first initial REGISTER received after the switchover for an AoR). Afterwards, the check is again based on the IP/port. 

Note: You must enable Multiple Contacts Per Aor to use this flag.

• Disabled (default)
• Enabled

(For S-SBC / I-SBC in 1:1 deployments only)

Enable this flag to use the SIP Bulk Status For Subscribers feature. 

• Disabled (default)
• Enabled

Enabling SIP Bulk Status For Subscribers gives you the ability to collect status files for the following after performing three dump requests over CLI or RESTCONF API:

• • Status of all Active registered endpoints. 
  • The Deleted Registers table, which includes the last deleted (or expired) registered endpoints.
  • All subscriptions generated by the SBC – specifically, SIP Generated Subscription Status – and the status for SIP endpoints.

Additional details: 

• Address Context - SIP Generated Subscription Status – View dump statistics
• SIP Registration – Feature description