The SaMOG Gateway can create sessions based on either of the following messages as a trigger:
RADIUS Access-Request messages: The Access Points (AP) or WLCs are configured with the SaMOG Gateway acting as the AAA Server. When the subscriber's user equipment (UE) performs an 802.11 association, these APs or WLCs trigger a RADIUS Access-Request message towards the SaMOG Gateway.
DHCP messages: The AP or WLC forwards DHCP messages (DHCP discover or DHCP Request) from the UE to the SaMOG Gateway over the EoGRE tunnel. The SaMOG Gateway uses this DHCP message as a trigger to initiate a session. This method of session creation is suited in networks where the AP or WLC is not capable of forwarding RADIUS messages.
RADIUS Accounting-based Session Creation
With the RADIUS Accounting-based Session Creation feature, sessions can be created when the APs forward a RADIUS Accounting-Start message with the allocated UE's IP address towards the accounting server. This method of session creation is suited in networks where the APs do not have EoGRE capabilities. These APs are configured with DHCP servers and the UE's IP address is allocated locally by the AP.
The SaMOG Gateway performs RADIUS-based authentication towards 3GPP AAA server by mapping parameters received in RADIUS Accounting request from the AP to a RADIUS Access-Request message towards the AAA server. The SaMOG Gateway perform APN-based local offload, using a Local P-GW for all accounting triggered sessions. The local P-GW allocates an IP address for the session. SaMOG performs a static NAT between the UE's IP address (shared by the AP in the Framed-IP-Address attribute of the accounting message) and the IP address assigned by the local P-GW.
Relationship to Other Features
DHCP Triggered and RADIUS (Authentication)-based Session Creation
DHCP triggered and RADIUS (authentication) triggered sessions can co-exist with the RADIUS Accounting-based sessions if the AP initiating the sessions are on different TWAN profiles. These TWAN profiles must have a corresponding session trigger configured.
The RADIUS Accounting-based sessions can be recovered for both unplanned failures and planned migrations.
The SaMOG Gateway supports RADIUS Accounting-based session creation on the TAL phase of both Web Authorization and Optimized Web Authorization features. Session redirection is performed using the local P-GW.