Figure: GTP–MBH AA deployment displays the GTP-MBH AA deployment.
In addition to SeGW FireWall deployments that require AA to support handling of GTP encapsulated traffic (S1-U interface), there are a number of deployments that require AA to support detection such as, classification and control of traffic encapsulated within GTP tunnels. These deployments are very similar in nature to AA support for other tunneling mechanisms such as 6RD, 6to4, DS-Lite. and so on For GTP tunnels, two main deployment use cases are identified: WiFi offload and mobile backhaul.
In Mobile Backhaul (MBH) deployment, operators provide business network services called Mobile Data Roaming traffic service (that is, GPRS roaming exchange/service) to Mobile Network operators (MNOs) using MPLS network. MNOs, in turn, use MBH networks to create GTP tunnels across the MBH network between their mobile access network (for example, eNBs/SGSN/SGW) and PGSN/PGW network devices.
MNOs look into their MBH network providers to provide more analytical reporting of the applications running over the GTP-U tunnels.
AA-ISA is used to report on diverted business SAPs, regardless of how the traffic is encapsulated (GTP-U and 6RD, for example). From AA-ISA point of view, the diverted business SAP represents the subscriber. The subscriber is the MNO itself. No transit AA subscriber support is required in this deployment.
In this situation, multiple GTP-U tunnels are carried per SAP. AA reports on the actual content of these tunnels and not on the GTP-U tunnel themselves. For example, AA reports on the applications per SAP and not applications per GTP-u tunnel.
While this use case does not require any form of AA control functions, all AA actions/control functions can be used except for actions that require packet modifications (such as HTTP enrichments, HTTP redirect, remarking, DSCP Remark, HTTP notification).