1 tosca_definitions_version: tosca_simple_yaml_1_0_0
4 A Proxy-CSCF (P-CSCF) is a SIP proxy that is the first point of contact for the IMS terminal.
5 It can be located either in the visited network (in full IMS networks) or in the home network
6 (when the visited network is not IMS compliant yet).
7 Some networks may use a Session Border Controller (SBC) for this function.
8 The P-CSCF is at its core a specialized SBC for the User network interface which not only
9 protects the network, but also the IMS terminal.
10 The use of an additional SBC between the IMS terminal and the P-CSCF is unnecessary and
11 infeasible due to the signaling being encrypted on this leg.
12 The terminal discovers its P-CSCF with either DHCP, or it may be configured
13 (e.g. during initial provisioning or via a 3GPP IMS Management Object (MO))
14 or in the ISIM or assigned in the PDP Context (in General Packet Radio Service (GPRS)).
18 derived_from: tosca.nodes.SoftwareComponent
21 type: tosca.capabilities.Endpoint.Public
22 relationship: tosca.relationships.ConnectTo
23 occurrences: [0, UNBOUNDED]
24 description: Connection with one ore more UAs
27 capability: tosca.capabilities.Endpoint
28 node: att.nodes.ims.ICSCF
29 relationship: tosca.relationships.ConnectsTo