6.7 S2c based IP flow mobility Routing rule
23.2033GPPPolicy and charging control architectureRelease 17TS
6.7.1 General
The clause 6.7 refers to UE based IP flow mobility as described in TS 23.261 [23].
The routing rule comprises the information that is required for the PCRF to install the QoS rules for a service data flow at the right BBERF in flow mobility scenarios. The PCRF relies on the IP flow mobility routing information contained in the IP flow mobility routing rule to the applicable BBERF for each PCC/QoS rule. The IP flow mobility routing rules are provided by the PCEF to the PCRF during IP‑CAN session establishment or modification.
The PCEF derives IP flow mobility routing rules based on flow binding information received from the UE as described in TS 23.261 [23].
Table 6.7 lists the information contained in a routing rule, including the information name, the description and whether the PCEF may modify this information in an updated version of the rule. The Category field indicates if a certain piece of information is mandatory or not.
Table 6.7: The routing rule information
|
Information name |
Description |
Category |
PCEF permitted to modify in an update |
|---|---|---|---|
|
Rule identifier |
Uniquely identifies the routing rule within an IP‑CAN session. It is assigned by the PCEF. |
Mandatory |
No |
|
Routing information |
This clause defines the method for detecting packets belonging to a flow and the route for the flow. |
||
|
Precedence |
Determines the order, in which the routing filters are applied. |
Mandatory |
Yes |
|
Packet filter |
A list of packet filters for the detection of IP flows. |
Mandatory |
Yes |
|
IP flow mobility Routing Address |
The IP flow mobility Routing Address that the matching IP flows use. |
Mandatory |
Yes |
The Rule identifier shall be unique for a routing rule within an IP-CAN session. It is assigned by the PCEF.
The Precedence defines in what order the routing rules is used by the PCRF to determine where to route a service data flow. The Precedence is derived from the priority included in the Binding Update as specified in TS 23.261 [23].
The Packet filter may comprise any number of packet filters, containing information for matching service data flows. The format of the packet filters is the same as the service data flow filter described in clause 6.2.2.2. A default packet filter can be specified by using wild card filter.
The IP flow mobility Routing Address identifies the IP address to be used for all service data flows matching the packet filters specified for this routing rule. The IP flow mobility Routing Address can be equal to the care-of address, or to the UE IP address (home address) in case of home link operations.
6.7.2 Routing rule operations
IP flow mobility routing rule operations consist of installation, modification and removal of routing rules.
During installation of a routing rule, the PCEF provides the routing rule information to the PCRF via the Gx reference point. The PCRF uses all the installed routing rules related to an IP‑CAN Session to select BBERF for any service data flow related for that IP-CAN Session.
The PCEF may, at any time, modify or remove an installed routing rule based on updated flow binding information received from the UE as described in TS 23.261 [23].