dsTest supports the GPRS Tunneling Protocol Version 1 control plane (GTP-Cv1) and GTP-U data plane over the signaling interface, the GTP interface used between the Serving GPRS Service Node (SGSN) and the GPRS Gateway Serving Node (GGSN).
The Gn Interface Application, along with other dsTest interface applications available provide dsTest users with comprehensive 3G data network testing capability . dsTest maintains a comprehensive set of Operational Measurements for the Gn interface.
You can initiate the following control events for a GTP Serving Node (GSN):
- Create PDP Context Request/Response
- Update PDP Context Request/Response
- Initiate PDP Activation Request/Response
- Delete PDP Context Request/Response
A complete set of events that can be generated with the Gn interface can be found here.
GTP-C Initiator Simulation (GGSN Testing)
Verify context creation by sending Create PDP Context Requests from a simulated SGSN node to a GGSN under test will properly active a PDP context either primary and secondary contexts. Insure that the GGSN sends a correct response to the request.
Verify that the GGSN frees up resources when a Delete PDP Context Request is received from the SGSN as part of the Detach procedure or the PDP Context Deactivation procedure.
GTP-C Responder Simulation (SGSN Testing)
Simulate GTP-C interfaces to your SGSN. Verify that the SGSN correctly interprets the GGSN responses. For example, test the following scenarios:
- Simulate bearer activation by initiating a Create PDP Context from your SGSN and verify that it correctly processes both positive and negative responses from the simulated GGSN.
- After sending the Create PDP Context Request message, verify the SGSN marks the PDP context as “waiting for response”, and accepts GTP PDUs from the GGSN but does not send these GTP PDUs on to the UE.
- The SGSN should interpret a valid request with the initiation of the creation of a tunnel between a PDP Context in the SGSN and a PDP Context in the GGSN. Verify that the procedure is repeated if not successfully completed, and that the SGSN repeats the Create PDP Context Request message to the next GGSN address until no more GGSNs are available, at which time the SGSN fails the activation procedure.
- Verify that your SGSN retains bearer information and attributes, and, upon location changes, sends an Update PDP Context Request and correctly processes the response from the simulated GGSN.
- When the simulated GGSN sends an Initiate PDP Context Activation Request message to the SGSN, verify that the SGSN initiates the Secondary PDP Context Activation Procedure for network requested bearer control.
- Verify that your SGSN sends a Delete PDP Context Request to the GGSN as part of the GPRS Detach procedure or the GPRS PDP Context Deactivation procedure, and that the SGSN processes a Delete PDP Context Request from the GGS as part of the PDP Context Deactivation Initiated by the GGSN.
Test the capacity and performance of your SGNs by using SmartEvents with other dsTest interface applications to trigger network-initiated events and validate the resulting GTP-C signaling at network rates.
You can create GTP state machines and use them in combination with our PCC interface applications to test gateway elements, including dynamic policy enforcement, in the mobile packet core. Our SmartEvents feature can coordinate other interface applications to trigger network-initiated events from our Emulators and validate the resulting GTP-C signaling.