In this section:
Overview
The SBC Core supports Application Layer Forking feature to receive a single initial INVITE at the ingress leg and send multiple INVITEs with different Call-IDs to different destinations on the egress leg. The first answered call is considered as active, and the SBC terminates the other calls gracefully by sending a CANCEL message. The SBC exposes a single dialog and a single media stream on the ingress leg while forking to multiple dialogs and exposing multiple media streams on the egress leg. If different end devices with unique Address of Records (AoRs) in an enterprise exist, the SBC maintains an AoR group to perform Call Forking. For example, if an enterprise contains three end devices with the following AORs: tel: +18041774568 sip: +18041774568@mydomain.com Sip: jack@mydomain.com All of the above AoRs are grouped under an AoR Group and enabled for call forking. When there is an incoming call to any one of the AoRs, the call is forked to all the AoRs in this group. To support call forking feature, the In external PSX, the flag The SBC supports following timers related to SIP forking: Native Call Forking does not support GW-GW scenarios.aorGroupProfile
parameter is added to profiles
configuration.Enable Call Forking
is used to enable or disable the call forking functionality. However, this flag is not available in the SBC (ERE). The SBC performs VOIP Subscriber dip to determine the AoR Group. If AoRs are found for the VOIP subscriber, the call is forked to different AoR devices.
Perform the following steps to configure call forking feature in the SBC:
- Configuring AoR Group Profile
- Configuring the VOIP Subscriber
- Configuring Routing for the AoR Group Profile
- Configuring Preferred Identity Parameter (Optional)
- Enabling Preferred Identity in the SIP Trunk Group (Optional)
- Viewing the Configuration
Configuring AoR Group Profile
Execute the following command to configure AoR Group Profile:
% set profiles aorGroupProfile AR2 aorDataList sip:123@ss.com;1111;2222;user=phone,sip:456@yy.com;0;0;user=phone aorDialogAttribute useFirst18x % commit
Configuring the VOIP Subscriber
% set profiles voipSubscriber sip:EXAMPLE@RIBBON.com aorGroupProfile AR2 egressRURIAttribute aorEgress % commit
Configuring Routing for the AoR Group Profile
To configure routing for the AoR Group Profile, refer to the section Basic Call Flow Using ERE.
Configuring Preferred Identity and Wait for Answer Parameters (Optional)
% set profiles aorGroupProfile AR2 preferredIdentity sip:123@ss.com waitForAnswer 0 % commit
Enabling Preferred Identity in the SIP Trunk Group (Optional)
% set addressContext default zone defaultSigZone sipTrunkGroup TG1 policy preferredIdentity enable % commit
Viewing the Configuration
To view the AoR Group profile, execute the following command:
% show profiles aorGroupProfile AR2 aorDataList "sip:123@ss.com;1111;2222;user=phone sip:456@yy.com;0;0;user=phone"; preferredIdentity sip:123@ss.com; aorDialogAttribute useFirst18x; waitForAnswer 0; [ok]
To view the VOIP Subscriber, execute the following command:
% show profiles voipSubscriber voipSubscriber sip:EXAMPLE@RIBBON.COM { aorGroupProfile AR1; egressRURIAttribute aorEgress; } voipSubscriber sip:EXAMPLE@RIBBON.com { aorGroupProfile AR2; egressRURIAttribute aorEgress; } [ok]
To view the the flag preferredIdentity
in the SIP Trunk Group, execute the following command:
> show table addressContext default zone defaultSigZone sipTrunkGroup TG1 carrier 0000; country 1; localizationVariant northAmerica; tgIPVersionPreference both-ipv4-and-ipv6; preferredIdentity enable; digitParameterHandling { numberingPlan NANP_ACCESS; } callRouting { elementRoutingPriority DEFAULT_IP; } media { packetServiceProfile DEFAULT; } services { classOfService DEFAULT_IP; } signaling { ipSignalingProfile DEFAULT_SIP; } featureControlProfile DEFAULT_IP; ingress { flags { nonZeroVideoBandwidthBasedRoutingForSip enable; nonZeroVideoBandwidthBasedRoutingForH323 disable; hdPreferredRouting disable; hdSupportedRouting disable; } } [ok]