Abstract: An example network access device (NAD) includes a network interface to send and receive packets with an authentication, authorization, and accounting (AAA) server, and a subscriber management service unit (SMSU). The SMSU is configured to, responsive to determining that the AAA server is not reachable by the NAD, send a message from the NAD to the AAA server using the network interface, wherein the message directs the AAA server to send a discovery request message to the NAD, receive the discovery request message from the AAA server using the network interface, wherein the discovery request message includes a request for information about a plurality of subscriber sessions, and generate a discovery response message that includes information about at least a portion of the plurality of subscriber sessions, and send the discovery response message to the network access device using the network interface.

Abstract: An example network access device (NAD) includes a network interface to send and receive packets with an authentication, authorization, and accounting (AAA) server, and a subscriber management service unit (SMSU). The SMSU is configured to, responsive to determining that the AAA server is not reachable by the NAD, send a message from the NAD to the AAA server using the network interface, wherein the message directs the AAA server to send a discovery request message to the NAD, receive the discovery request message from the AAA server using the network interface, wherein the discovery request message includes a request for information about a plurality of subscriber sessions, and generate a discovery response message that includes information about at least a portion of the plurality of subscriber sessions, and send the discovery response message to the network access device using the network interface.

Abstract: A multi-level table is searched for an item in an item database matching a search key. For example, a multi-level search table is searched for an identifier of an Internet Protocol prefix stored in a prefix database which most closely matches an Internet Protocol address. The search table may be modified in response to changes to the item database while the table is being searched. Default item identifier tables may be used to store default item identifiers which reduce the complexity of update operations.