Using Call Traces to Determine How and Why a CAMEL Voice Calls has Ended (Doc ID 1189943.1)

Last updated on JULY 21, 2023

Applies to:

Purpose

This article will take a detailed look at the signalling involved when mobile voice calls are ended, using the CAP (CAMEL Application Part) protocol, in Intelligent Networks (IN).   The intent is to give the reader the necessary knowledge to decode a traced call to understand when, how and why the call was ended.    Particular attention is also given to the differences between the ISUP release cause formats shown between a snoop trace, decoded in Wireshark (a protocol analyser), and the OCNCC's platforms own SCCP call tracing capabilities (refer to the OCNCC - SIGTRAN TCAP IF Technical Guide for more detail on SCCP tracing).

Scope

The following article is for Support Engineers involved in decoding traced voice calls and some understanding of the SS#7 (Signaling System 7) protocol suite is necessary as common reference to signalling terms and concepts will be used throughout the article.

The IN term SCP (Service Control Point) will be used and in the context of the OCNCC architecture this refers to the SLC (Service Logic Controller), or the legacy UAS (Universal Application Server), part of the system.

Out of scope for this article is how to trace a call using either; snoop or SCCP.

Details