The node allows the NAS-Port-Id to be carried within the Subscription-Id AVP. Because the NAS-Port-Id may not be unique network-wide (two independent nodes may use the same NAS-Port-Id), there is a need for another identifier in conjunction with NAS-Port-Id to make the Subscription-Id unique across the network. This additional identifier is a custom string that can be appended to the NAS-Port-Id. It is defined when the NAS-Port-Id is configured for inclusion in Gx messages. See the 7450 ESS, 7750 SR, and VSR RADIUS Attributes Reference Guide for information to format NAS-Port-Id AVP on the node.
The string can be used to identify the location of the node. For example:
@ALU-MOV-SITE-1
An example of the augmented NAS-Port-Id would look like:
NAS-Port-Id = lag-1.1/1/2:23.2000@ALU-MOV-SITE-1
where: 'lag-1.1/1/2:23.2000' is the part referencing the SAP on the node (port + vlan tags) and the '@ALU-MOV-SITE-1' is the node itself.
The NAS-Port-Id can be then inserted in the Subscription-Id AVP.