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.
When the SBC receives a REGISTER request from the SIP endpoint, it sends a policy request to the ERE (or centralized PSX) for the next-hop route to the SIP Registrar. Before forwarding the REGISTER request, the SBC creates a Path Header containing its own signaling IP address and port number and includes the Path Header in the outgoing REGISTER request. The reg-info parameter is added to the Path Header and used by the SBC to determine the next-hop direction of future INVITE requests.
When the SBC receives a 200-class response to a REGISTER request from the SIP Registrar, the SBC does not include the Path header when it sends the response to the SIP endpoint. SBC has the flexibility to transparently pass a single Path Header towards UE if no interworking is needed.
The following flags are associated with Path Header provisioning.
Create Path Header – When enabled, the SBC inserts Path Header on top of the received header or creates a new header in REGISTER request from a UE. (default is ‘disable’).
% set profiles signaling ipSignalingProfile <profile name> commonIpAttributes flags createPathHeader <enable|disable>
Store Path Header – When enabled, the SBC stores Path Headers received in a REGISTER request. (default is ‘disable’).
% set profiles signaling ipSignalingProfile <profile name> commonIpAttributes flags storePathHeader <enable|disable>
Add Path/Service Route Flag—When enabled, two Path/Service-Route Headers are added in REGISTER request from a UE. If disabled, only one Path/Service-Route Header is added (default is ‘disable’).
This flag applies only if createPathHeader is enabled.
% set profiles signaling ipSignalingProfile <profile> commonIpAttributes flags addPathServiceRoute <disable|enable>
Path Header Transparency Flag – When enabled, the SBC transparently passes the received Path Headers. (default is ‘disable’).
% set profiles signaling ipSignalingProfile <profile name> commonIpAttributes transparencyFlags pathHeader <enable|disable>