dsTest supports both server emulation and client simulation capabilities for the Base Station subsystem Application Part (BSSAP) Gs interface. Test Serving GPRS Support Node (SGSN) Gs interfaces in UMTS or LTE networks with our Visitor Location Register (VLR) Emulator. Use the Gs Interface application on our SSGN node to test the capacity and performance of a VLR. For more information regarding how to use dsTest for BSSAP+ functional and compliance testing, see our page on Conformance Testing. The Gs interface is specified in 3GPP TS 23.272 and 3GPP TS 29.018.
A comprehensive set of operational measurements is collected at specified intervals and stored in a SQLite database on the dsTest server. Real-time measurements may be retrieved through our dsClient CLI interface or graphed via our dsClient GUI interface.
The Gs Interface application implements the following BSSAP+ procedures when associations between an SGSN and a VLR have been established:
- Paging for non-GPRS Services;
- Location Update for Non-GPRS Services;
- Non-GPRS Alert;
- Explicit IMSI Detach from GPRS Services;
- Explicit IMSI Detach from Non-GPRS Services;
- Implicit IMSI Detach from Non-GPRS Services;
- VLR Failure;
- SGSN Failure;
- MS Information.
A complete set of events that can be generated with the Gs interface can be found here.
The VLR emulator participates in SGSN-initiated procedures such as Location Updates or a Detach when indicated, eliminating the need to dedicate a production server to lab activities. You can manually trigger VLR-initiated procedures such as Paging or Non-GPRS Alert by executing a test event chain with a run-time command or during an automated test.
VLR Testing (Client Simulation)
The Gs Interface application simulates an SGSN’s Gs interface to determine the impact of new VLR features and standards before they are deployed in a network. The Gs Interface application allows you to validate VLR performance and capacity in a realistic network environment, replicating the deployment configuration.
Execute timed chains of test events with a run-time command or during an automated test to trigger client-initiated procedures.
- Start and stop specified subscriber sessions, simulating real-world subscriber activity
- SGSN failures
Multiple SGSN nodes can be instantiated on a single server, each with scalable subscriber loads and transaction rates. In this mode, up to 1000 independent SGSN nodes may be simultaneously simulated and SGSN-SGSN mobility may be simulated. The nodes are fully independent and their subscriber configurations may be independent, overlap, or be duplicated.