Policy co-ordination in a communications network
In order to address the problem of allowing a GGSN of a UMTS core network to work towards multiple Policy Control Functions (PCFs) co-located with P-CSCF nodes using the COPS protocol, a policy control function coordinator (PCF-C) is implemented between the GGSN and the P-CSCF. A single COPS connection is established between the GGSN and the PCF-C while a COPS connection is established between the PCF-C and each of the P-CSCF nodes. Decisions made at the PCFs are routed to the GGSN via the PCF-C, and responses generated at the GGSN are routed to the appropriate PCFs via the GGSN. This architecture avoids conflicts which might otherwise arise with the COPS protocol.
1. In a mobile telecommunications network a method of notifying a first policy enforcement point (PEP) node of policies and/or policy decisions made at a plurality of policy decision point (PDP) nodes, the PEP and the PDP nodes adapted to communicate with one another via an IP network using the Common Open Policy Service (COPS) protocol, the method comprising:
establishing a single COPS connection between the PEP node and a coordination node also coupled to the IP network;
establishing a COPS connection between the coordination node and each of the PDP nodes;
sending decisions from the PDP nodes to the coordination node over the respective COPS connections and, at the coordination node, recording the sources of the decisions and forwarding the decisions to the PEP node over the COPS connection; and
sending responses to decisions from the PEP node to the coordinating node over the single COPS connection and, at the coordinating node, identifying the source PDP nodes of the decisions based upon the recorded sources and forwarding the responses to the respective PDP nodes over the respective COPS connections.
2. The method of claim 1 , wherein said third network node records the identity of the originating second network node for each decision received by it and routes responses received from the first network node according to the recorded information.
3. The method of claim 1 , wherein the PEP node is a Gateway General Packet Radio Service Support Node, GGSN, of a data network within the mobile telecommunications network and the PDP nodes are Proxy-Call State Control Function (P-CSCF) nodes of an IP Multimedia Core Network Subsystem (IMS) the P-CSCF nodes implementing a Policy Control Function for the GGSN.
4. In a mobile telecommunications network, a method of enabling a policy enforcement point (PEP) node to be notified of policies and/or policy decisions made at a plurality of policy decision point (PDP) nodes, the PEP and the PDP nodes adapted to communicate with one another via an IP network using the Common Open Policy Service (COPS) protocol, the method comprising,
at a coordinating node coupled to the IP network:
establishing a single COPS connection to the PEP node;
establishing a COPS connection with each of the PDP nodes;
receiving decisions from the PDP nodes over the respective COPS connections, recording the sources of the decisions, and forwarding the decisions to the PEP node over the COPS connection; and
receiving responses to decisions from the PEP node over the COPS connection, identifying the source PDP nodes of the decisions based upon the recorded sources, and forwarding the responses to the respective PDP nodes over respective COPS connections.
5. The method of claim 4 , wherein said coordinating node records the identity of the originating PDP node for each decision received and routes responses received from PEP node according to the recorded information.
6. The method of claim 4 , wherein said PEP node is a Gateway General Packet Radio Service Support Node (GGSN) of a data network within a mobile telecommunications network and said PDP nodes are Proxy-Call State Control Function (P-CSCF) nodes of an IP Multimedia Core Network Subsystem (IMS), the P-CSCF nodes implementing a Policy Control Function for the GGSN.
7. In a mobile telecommunications network, an apparatus for enabling a policy enforcement point node to be notified of policies and/or policy decisions made at a plurality of second policy decision point nodes, the PEP and the PDP nodes adapted to communicate with one another via an IP network using the Common Open Policy Service, COPS, protocol, the apparatus comprising:
input output means coupled to the IP network;
a first processor means coupled to the input output means adapted to establish a single COPS connection the PEP node;
a second processor means coupled to the input output means adapted to establish a COPS connection with each of the PDP nodes;
a third processor means coupled to the input output means adapted to receive decisions from the PDP nodes over the respective COPS connections, recording the sources of the decisions, and forwarding the decisions to the PEP node over the COPS connection; and
a fourth processor means coupled to the input output means and adapted to receive responses to decisions from the PEP node over the COPS connection, identifying the source PDP nodes of the decisions based upon the recorded sources, and forwarding the responses to the respective PDP nodes over respective COPS connections.
8. The apparatus of claim 7 , wherein the apparatus is a General Packet Radio Service Gateway Support Node (GGSN) for use in providing a General Packet Radio Service (GPRS) packet switched service.
9. A coordinating node in a network for enabling a policy enforcement point (PEP) node to be notified of policies and/or policy decisions made at a plurality of policy decision point (PDP) nodes, the PEP and the PDP nodes communicating with one another via an IP network using the Common Open Policy Service (COPS) protocol, the coordinating node comprising:
means for establishing a single COPS connection to the PEP node;
mean for establishing a COPS connection with each of the PDP nodes;
means for receiving decisions from the PDP nodes over the respective COPS connections, recording the sources of the decisions, and forwarding the decisions to the PDP node over the COPS connection; and
means for receiving responses to decisions from the PEP node over the COPS connection, identifying the source second nodes of the decisions based upon the recorded sources, and forwarding the responses to the respective PDP nodes over respective COPS connections.
10. The method of claim 9 , wherein said coordinating node records the identity of the originating PDP node for each decision received and routes responses received from the PEP node according to the recorded information.
11. The method of claim 9 , wherein said PEP node is a Gateway General Packet Radio Service Support Node (GGSN) of a data network within a mobile telecommunications network and said PDP nodes are Proxy-Call State Control Function (P-CSCF) nodes of an IP Multimedia Core Network Subsystem, (IMS) the P-CSCF nodes implementing a Policy Control Function for the GGSN.
12. A system in a mobile telecommunications network, the system comprising:
a policy enforcement point (PEP) node;
a plurality of policy decision point (PDP) nodes, the PEP and the plurality of PDP nodes adapted to communicate with one another via an IP network using the Common Open Policy Service (COPS) protocol;
means for establishing a single COPS connection between the PEP node and a coordination network node coupled to the IP network;
means for establishing a COPS connection between the co-ordination network node and each of the PDP network nodes;
means for sending decisions from the PDP network nodes to the coordination network node over the respective COPS connections and, at the coordination network node, recording the sources of the decisions and forwarding the decisions to the PEP network node over the COPS connection; and
sending responses to decisions from the PEP network node to the coordination network node over the single COPS connection and, at the coordination network node, identifying the source PDP nodes of the decisions based upon the recorded sources and forwarding the responses to the respective PDP nodes over the respective COPS connections.
13. The method of claim 12 , wherein the coordination node records, the identity of the originating PDP node for each decision received and routes responses received from the PEP node according to the recorded information.
14. The method of claim 12 , wherein said PEP node is a Gateway General Packet Radio Service Support Node, GGSN, of a data network within the mobile telecommunications network and said PDP nodes are Proxy-Call State Control Function (P-CSCF) nodes of an IP Multimedia Core Network Subsystem (IMS) the P-CSCF nodes implementing a Policy Control Function for the GGSN.