Core Network Dynamics’ HSS is the first element of the product portfolio that has a data-sheet.
The Core Network Dynamics team has been developing HSS functionality for more than 10 years now. The history of the HSS is quite long, it appeared in the first drafts of IMS specifications and the first prototype was implemented as part of the OpenIMSCore. When the HSS became also relevant for LTE subscriber data and started claiming its role as the most important subscriber repository for the 4G mobile operators, CND re-factored and re-designed the IMS prototype to adapt it to the best design practices in software architectures and update it to the current standards. Today we are releasing its datasheet.
The OpenEPC HSS is now Release 12 compliant both for the IMS interfaces as for the EPC interfaces. It has a decoupled front-end and back-end design aligned with 3GPP UDR standards but not limited by them. The data-less front-end is our main delivery. It’s a high efficient Diameter component which handles transactions without storing state. For the back-end we support both SQL databases and LDAP repositories providing maximum flexibility. Our data-model is consistent and extensible.
Due to its architectural design scaling the HSS is easy. The back-end scales independently as SQL and LDAP repositories do. The front-end being data-less, can be scaled horizontally by simply adding new instances. A simple DRA, which can handle tens of thousands of Diameter transactions per second, load-balances the requests between the different front-ends. High-Availability and resiliency is also provided with our data-less front-end and standard back-ends approach.
CND does not provide performance data for the HSS in this datasheet since it depends on the setup used, as well as on the DBMS back-end of customer choice. We do have figures with our internal reference platforms but they are only representative for exactly the same setups. We will publish some performance results comparing different platforms in a separate blog post. For simplicity, usually a simple division by 10 (or less in many situations) of the number of Transactions-per-Second supported by the DBMS would yield the Diameter-Requests-per-Second system output. Through a highly efficient C-based implementation and the use of best-in-class Linux techniques, the CND HSS adds a very low overhead additional to the customer’s DBMS of choice.
Often when in a complex setup there are elements that need data from the HSS but do not support Diameter. In these cases there is a need for a MAP Gateway that provides interworking as specified by 3GPP IWF. CND can support customers with these issues providing the maximum flexibility.
Another key aspect of the HSS when it is used commercially is the interconnection to the Authentication-Center (AuC). The AuC is usually an element that hosts all the keys used by mobile subscribers with additional physical security features. Our internal AuC functionality can also be externalized and as such integrated with the AuC selected by the customer.
Provisioning is a key aspect when operating an HSS. CND web management interface is used for provisioning of individual subscriber data and scripts are available for bulk provisioning. Provisioning data directly to the back-end is also possible. The integrators and customers who select to provision directly make use of CNDs remote management interface when an operation should be triggered by the HSS due to the newly provisioned data. For example deregistering a user when it has been barred or pushing notifications to the elements subscribed to those events.