In this section:
The SBC Core supports SIP for Business (SIP-B) protocol which outlines advanced SIP features for business telephony networks. Example SIP-B features are shown below.
Ribbon recommends using the Transparency Profile to configure transparency on the SBC Core for new deployments, as well as applying additional transparency configurations to existing deployments. Do not use IP Signaling Profile flags in these scenarios because the flags will be retired in upcoming releases.
Refer to the SBC SIP Transparency Implementation Guide for additional information.
N-Way Calling
With N-way calling, multiple contacts are associated with the same Address of Record (AoR). A conference server returns back its identity in the user part of the Contact header in the 200 response for an INVITE request. It also includes focus parameter in the Contact header to indicate that it is a conference focus. When transparency is enabled for contact header then ‘infocus’ is passed transparently to the other side.
Example CLI command to enable N-way calling:
set global signaling sipSigControls multipleContactsPerAoR enabled
Instance-id
SIP-B uses Instance-id to identify a particular registering device. A "sip.instance" feature tag is used in the Contact header of SIP requests and responses. Each device is expected to provide a globally unique instance-id. The SBC does not need to rely on this value for its own processing. When transparency is enabled for contact header then instance id is passed transparently to other side.
P-Asserted-Identity
SIP-B uses P-Asserted-Identity to send called party identity. P-Asserted-Identity is allowed for certain request types. The SBC supports transparently passing this parameter.
Out-of-Dialog-REFER
If “relayNonInviteRequest” flag is enabled, Out-of-Dialog requests like REFER and SUBSCRIBE/NOTIFY are relayed using a route look-up to the ERE based on the request URI.
Example CLI command to enable relayNonInviteRequest flag:
set addressContext default zone defaultSigZone sipTrunkGroup DALSG signaling relayNonInviteRequest enabled