Services using UCAI do not work with the VSSP process showing the error of type "timeout xx in state WaitRAB"

(Doc ID 1266971.1)

Last updated on SEPTEMBER 16, 2016

Applies to:

Oracle Communications Network Charging and Control - Version: 3.1.0 and later   [Release: 3.1.0 and later ]
Oracle Solaris on SPARC (64-bit)

Symptoms

First Symptom : The Service

A service built on the UCAI (Universal Call Agent for ISUP) interface does not work any more, or partially fails: a portion or all calls do not complete.
Ex: USSD Call Back is an example of such a service. It uses VSSP (Virtual Service Switching Point) to initiate the ISUP signalling and create both A and B legs of the call back call.

Second Symptom : The system log files

The vssp log file usually is /IN/service_packages/VSSP/tmp/vssp.log . It might however be different if the default configuration was altered.

The vssp log file will show error messages similar to:

09:18:34.095 VSSP 287/10/30,287/10/62 timeout 16 in state WaitRAB.
09:18:34.096 ISUP 287/10/62 tx RSC.

... a few seconds later ...

09:18:49.096 VSSP 287/10/30,287/10/62 timeout 16 in state WaitRAB.
09:18:49.096 ISUP 287/10/62 tx RSC.

... a few seconds later ...

09:19:04.097 VSSP 287/10/30,287/10/62 timeout 16 in state WaitRAB.
09:19:04.097 ISUP 287/10/62 tx RSC.

... and so on ...

... and a few minutes later ...

09:39:00.459 VSSP 287/10/30,287/10/62 leg A and B:1200:Reset circuit ignored!
09:39:00.460 VSSP 287/10/30,287/10/62 timeout 17 in state WaitRAB.

Key aspects to remember about that error messages sequence:

For each circuit, the first "timeout 16" is normal, UCAI requests the circuit to be reset as it has just restarted.
"timeout 16" messages will disappear some time after the restart and be replaced by the "timeout 17" together with the "Reset circuit ignored!" error message.

Changes

UCAI

    • m3ua configuration file (usually /IN/service_packages/etc/m3ua.config) that modifies the configuration of PC (Point Codes)
    • vssp configuration file (usually /IN/service_packages/etc/vssp.config) that adds or changes CIC's to the configuration

ITP

    • Routing, in, out, or any m3ua translation that affects proper transmission of RSC and RLC ISUP messages.

Core network

    • Any configuration that affects the proper answer, reaction and transmission of the RLC ISUP messages.

Cause

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