29.2093GPPPolicy control over Gq interfaceRelease 6TS
For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905  and the following apply:
Application Function (AF): element offering applications that require the control of IP bearer resources.
NOTE: The AF is capable of communicating with the PDF to transfer dynamic QoS-related application information. One example of an AF is the P-CSCF of the IM CN subsystem.
AF session: established by an application level signalling protocol offered by the AF that requires a session set-up with explicit session description before the use of the service
NOTE: One example of an application session is an IMS session.
AF session signalling: used to control the AF session
NOTE: One example of AF session signalling is SIP/SDP.
Attribute-Value Pair (AVP): See RFC 3588 , corresponds to an Information Element in a Diameter message.
For the purpose of the present document, the abbreviations given in 3GPP TR 21.905  and the following apply:
AF Application Function
AVP Attribute-Value Pair
GCID GPRS Charging ID
IANA Internet Assigned Numbers Authority
NASREQ Network Access Server Application
P-CSCF Proxy – Call Session Control Function
PDF Policy Decision Function
SBLP Service Based Local Policy
SDI Session Description Information