A single layer 3 connection can be used between the SBC (Session Border Controller) and Lotus Sametime Unified Telephony for branch user connecting to the Lotus Sametime Unified Telephony via a central SBC.
In order to use this functionality an EP (Endpoint) for each branch must be created. The EP needs to be a statically registered EP with the IP address/port of the interface created on the core side of the SBC for branch users connecting to the Lotus Sametime Unified Telephony. The alias name of the EP should also be the IP address of the interface created on the core side of the SBC.
Ensure that Registration Randomization is enabled in Lotus Sametime Unified Telephony.
The following endpoint attributes must also be set:
SIP ProxyParent topic: SBC (Session Border Controller)
Route via Proxy
RTP (Real-time Transport Protocol) configuration parameter (Srx/Sip/EnableProxyRegistration must be set to a value of true)
If a survivable branch proxy is used, the EP shall be marked as survivable.
The Lotus Sametime Unified Telephony registration renewal option should be enabled.