DHCP transit IP AA subscribers at DHCP relay node

DHCP-based transit sub creation provides a sub ID and lease time for IP addresses correlated to the ESM/subscriber context in the PE.

The 7750 DHCP relay agent creates dynamic DHCP AA subscribers when the DHCP ACK is received from the DHCP server, including the sub name, IP address and app-profile from DHCP Option 67 (if present) when the DHCP ACK messages passes through AA node to the downstream subscriber-edge node. If there is no app-profile assigned when the transit AA subscriber is created, a default transit AA subscriber app-profile is used (configured in the transit-ip-policy assigned against the divert parent AA subscriber).

This is compatible with the ESM router edge as well as third-party BRAS and CMTS.

Dynamic AA subscriber stats records are persistent across modem reset/session releases. The end of accounting records are created when transit subs are released.

Multiple IPs per transit AA subscriber are determined by seeing a common the DHCP Option 82 cct ID.