Understanding Selection of Properties for an IP-Based TDF Subscriber
When the Service Control Gateway receives a RADIUS accounting start request from the access network’s gateway GPRS support node (GGSN), Packet Data Network Gateway (PGW), or broadband network gateway (BNG) for an IP-based subscriber, it needs to select the properties to apply to a subscriber by selecting a traffic detection function (TDF) domain before setting up a TDF subscriber session. The domain-selection configuration identifies the values that various AVPs (such as the 3GPP IMSI or the IPv4 address) in the RADIUS request must match to select a particular TDF domain. For RADIUS requests that were snooped, the domain-selection configuration can identify the snoop segment that matched the request.
The domain-selection configuration includes one or more term statements, each of which includes from statements that must all be matched, and a then statement that identifies the name of the TDF domain. When a term matches, further terms are not evaluated if a PCEF profile is specified in either the selected TDF domain or in the then statement. If a PCEF profile is not specified in either the selected TDF domain or in the then statement, further terms are evaluated to find a PCEF profile for the subscriber.
If no TDF domain is selected, then the TDF subscriber session is not set up.
Before you can configure the TDF domain selection, you must configure a TDF gateway, the TDF domains, and the RADIUS client.
The match conditions for TDF domain selection include:
(Not applicable to snooped messages) The RADIUS client (GGSN, PGW, or BNG) that is sending the accounting start request
Values for called-station-id, calling-station-id, class, framed-ip-address, framed-ipv6-prefix, 3gpp-imsi, nas-ip-address, or user-name AVPs
Values for other AVPs you identify
Figure 1 shows an overview of the IP-based subscriber setup process.