Disclosed are apparatus and methods for managing session data in a session border controller (SBC), where the session data is sent from a first node, such as a first phone, to a second node, such as a registrar or second phone. In one example embodiment, the following operations are performed in a first intermediary node that is configured to provide network address translation (NAT) for both a header and payload of a session packet and has an inside interface coupled with a second intermediary node that is configured to perform NAT for only a header of session packets. It is determined whether an end node is sending session packets that are not used to set up a session and that result in a binding that was formed by the second intermediary node being retained. The binding associates inside and outside addresses of the end node, and an end node is defined as a node that originates a session packet. It is determined whether to inhibit a registration throttling process from being performed by the first intermediary node, that results in the binding being retained, based on whether it is determined that the end node is sending session packets that are not used to set up a session and that result in the binding being retained.