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Core Network Testing

NG40 as HLR/HSS Nodal Emulator and Nodal Tester


In every mobile network there is one database required for the storage of permanent and temporary subscriber information. This entity is commonly known as Home Location Register (HLR) or Home Subscriber Server (HSS). The most important permanent information stored in this database are an unique subscriber identifier (IMSI) and a secret key (ki). Temporary information are - among others - required for mobility management. Parameters like Mobile Country Code, Mobile Network Code, Location Area, Routing Area and Tracking Area specify subscribers current location. Without these information it wouldn't be possible to transfer a call to the correct geographic destination.

The Home Location Register was originaly based on E1-links and all procedures from/to the HLR were encapsulated into TCAP/MAP protocol messages, specified in ETSI 09.02. During the transition from E1 to Ethernet (Mobile-IP convergence) it was necessary to adjust the lower protocol layers. The adaptation layers introduced (e.g. M3UA) resulted in additional protocol overhead. The entire protocol stack became more complex. In 4G networks the complete MAP functionality has therefore been replaced by a protocol called DIAMETER. For the sake of simplicity: SCCP and TCAP has been made redundant.

The protocol stack evolution is shown at the diagram below:

Protocol Stack
Product Variants

NG40 can simulate the functionality of MME, SGSN and MSC for HLR / HSS verification.

Besides, NG40 can replace real subscriber database(s) and generate all relevant protocol messages towards MME, SGSN and MSC (Devices Under Test).

NG40 generates MAP messages for the communication from/to HLR and DIAMETER messages for the communication from/to HSS.

For legacy reasons it is also possible to equip the NG40 server with SANGOMA E1/T1 interface cards and to test over the MTP protocol stack as depicted above.

Possible product variants as presented below:

HLR/HSS product variants
NG40 as HLR/HSS Emulator – Product Capabilities

NG40 can act as a stand-alone HLR (NG40–HLR-EIR for MAP), as a stand-alone HSS (NG40–HSS-EIR for DIAMETER) or as a combined solution. A combined HLR/HSS emulator is useful for the concurrent simulation of 2G, 3G and 4G subscribers, e.g. for 2G/3G/4G handover tests and for the verification of 2G/3G fallback scenarios.
NG40 supports the following procedures:

  • Location Update
  • Location Update
  • Cancel Location
  • Cancel Location
  • Purge UE
  • Insert Subscriber Data
  • Delete Subscriber Data
  • Reset
  • Send Authentication
  • Send Authentication
  • Send Routing Info
  • Send Routing Info
  • Provide Roaming Number
  • Provide Roaming Number
  • Notification
  • ME Identity Check
Product Features
  • Demonstrational, Functional, Load and Capacity Tests
  • EIR functionality included
  • HLR/EIR and HSS/EIR as Test Component as well as Device Unter Test
  • Supported interfaces: C, F, Gr, Gf, S6a, S6d, S13, S13'
  • 25.000 MAP msg/sec
  • 25.000 Diameter msg/sec
  • 2.000.000 emulated mobile subscribers

ng4T offers these and other advanced solutions for core network testing.

Don't hesitate to contact us if you have any specific request!

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