In some migration scenarios (where branch SBCs (Session Border Controllers) already exist and a new central SBC is being added) or hosted scenarios (e.g. where direct media connection is allowed only between branches of the same customer), SBCs may be deployed in branch offices and an SBC may also be deployed as a media relay SBC in the data center.
A central SBC may also be necessary to provide firewall pinholing if there are firewalls present between the branch SBC and the data center. In scenarios where a customer requires a SIP-aware Firewall (with port pinholing) in the branch as well as in the data center, then cascaded SBCs may be necessary. The cascaded SBC configuration is not supported as a standard solution, but may be deployed on a project specific basis.
Parent topic: SBC (Session Border Controller)