使用自带HLR模拟器测试GMLC时遇SCCP路由错误致请求无法路由

Problem Overview #

I'm running tests on a GMLC server using its built-in HLR simulator. When executing the following GMLC request:

curl -X POST 171.10.30.19:8280/restcomm/gmlc/rest?msisdn=8476302000

I hit an SCCP routing error that blocks the HTTP request from being routed successfully. Relevant log snippets are shown below:

15:15:12,147 WARN [SccpStackImpl-SccpStack] (pool-33-thread-1) Rx : MTP-RESUME: AffectedDpc=2
15:16:09,095 WARN [SccpRoutingControl] (SLEE-EventRouterExecutor-7-thread-1) Received SccpMessage=Sccp Msg [Type=-1 networkId=0 sls=1 incomingOpc=-1 incomingDpc=-...

Key Troubleshooting Steps #

Let’s walk through actionable steps to diagnose and resolve this issue:

• Validate SCCP Route Table Entries
  The log mentions AffectedDpc=2—check if this destination point code is properly configured in your GMLC’s SCCP routing table. Ensure the entry includes the correct originating point code (OPC), DPC, signaling link set details, and routing priority.

• Check MTP Layer Health
  The MTP-RESUME warning indicates the MTP link to DPC=2 recently recovered. Confirm the MTP layer is fully operational: verify link status, check for congestion or ongoing failures in the signaling path, and ensure the link is properly bound to the SCCP stack.

• Fix Invalid SCCP Message Type
  The log shows Type=-1 for the incoming SCCP message, which is an invalid/unknown type. This could stem from a protocol mismatch (e.g., ITU vs. ANSI SCCP) between the GMLC and HLR simulator, or incorrect message encoding in the simulator. Double-check that both endpoints use the same SCCP protocol variant and message formatting rules.

• Verify MSISDN-to-DPC Mapping
  Ensure the MSISDN 8476302000 is correctly mapped to the target HLR (DPC=2) in the GMLC’s subscriber data or routing rules. A missing or incorrect mapping will cause the GMLC to fail routing the request to the right endpoint.

• Retrieve Full SCCP Log Details
  The truncated log entry cuts off critical addressing parameters (incoming OPC/DPC values). Pull the complete SCCP message log to identify if invalid addressing fields are triggering the routing control warning.

Quick Initial Checks #

1. Restart both the GMLC server and HLR simulator to rule out transient state issues.
2. Confirm signaling links between the GMLC and simulator are provisioned correctly and show as active.
3. Test with a known-working MSISDN (if available) to isolate whether the issue is specific to this subscriber or a broader routing problem.

内容的提问来源于stack exchange，提问作者amagadum