Subscription Management

For the Release 1 of the OpenEPC project, the AAA component mainly targeted was the HSS (or SPR as referred to in 3GPP EPC terminology). As the Core Network Mobility Enabler for Release 1 are limited in scope, the main feature targeted here is the new Sp interface of the HSS. Further interfaces and AAA Servers and/or Proxies will be added to the project on demand.

1. OpenEPC Release 1 Home Subscriber Server / Subscription Profile Repository

The Home Subscriber Server component in the OpenEPC project, refered to as CHeSS, builds on the established experience gained during the development of  The Open IMS Core Project. Sharing the same database back-end with the open source  FHoSS component, it stays compatible with existing subscriber data. Being entirely implemented in C and now part of the Wharf platform, it offers a very high performance, limited only by the database back-end, allowing for  IMS/NGN Performance Benchmarking.

2. HSS Cx Reference Point

The Cx interface has been implemented according the  3GPP TS29.228 and  3GPP TS29.229 Release 7/8 specifications and validated against  The Open IMS Core Project. Support for all the Diameter messages is provided and the following authentication algorithms are supported:

•  RFC3310 Digest Authentication Using Authentication and Key Agreement (AKA) (Digest-AKAv1-MD5)
•  RFC4169 Digest Authentication Using Authentication and Key Agreement (AKA) Version-2 (Digest-AKAv2-MD5)
•  RFC2617 Digest Access Authentication (Digest-MD5), with specific variations as standardized by 3GPP Rel. 8/9, ETSI NGN Rel. 1/2 or CableLabs PacketCable 2.0

3. HSS Sh Reference Point

The Sh interface has been implemented according the  3GPP TS29.328 and  3GPP TS29.329 Release 7/8 specifications. Support for all the Diameter messages is provided, yet advanced Application Server features like Dynamic Service Activation (DSAI) are considered for the next release.

4. SPR Sp Reference Point

The Sp interface of the SPR function, although currently not standardized, has been derived from the Sh implementation according to the 3GPP EPC recommendations. Being part of the IMS HSS, together with the Cx and Sh interfaces, the common data is shared seamlessly. Currently there is no support for subscription/notification of information changes in the SPR. The following Data-Reference types have been defined and can be used to interrogate various SPR data:

• Subscription-Id - providing either an IMSI, MSISDN or IMPU, the SPR will respond with the associated MSISDNs, IMSIs or IMPUs
• Subscription-Data - providing an IMSI, MSISDN or IMPU, the SPR will responds the stored subscription profile, containing information like default QoS profiles, allowed/restricted services or access network restrictions
• APN-Configuration - providing an IMSI, the SPR will respond with the associated PDN context informations.