Dialogic IMG - GCL Rejects Incoming Calls With Cause Value 42 (Switching Equipment Congestion)

Table of Contents

1 Symptom:
2 Reason for the issue:
3 Product List
4 Glossary of Acronyms / Terms

Symptom:

A Dialogic IMG Integrated Media Gateway may reject incoming calls with a clearing cause value # 42 (switching equipment congestion. The IMG Call tracing log shows that the IMG GCL software component sent a Clear Response with cause value of 42. This happens only during periods of high traffic.

07:42:30.886 CALL(GCL) (00:00000:00) SENT Clear Response, cause=42 to L4
.....
07:42:30.886 CALL(SIP) (00:58132:00) Reason Hdr: "Switching equipment congestion"

Reason for the issue:

Cause value 42 (Switching equipment congestion) indicates that the switching equipment generating this cause is experiencing a period of high traffic.
The IMG GCL software component checks the current IMG CPU busy percentage, and will reject calls when IMG CPU exceeds the 85% busy limit.

Steps to check the GCL statistics of CPU overload:

Telnet to the IMG 1004 / IMG 1010, or ssh to the IMG 2020
Type

d to enter the Advanced Menu, log in with admin / password

Type

G to enter into GCL Diagnostics

Type

C to "Display stats of CPU overload"

G
gcl> C

GCL CPU Overload Stats
CPU[85] calls rejected=37
Total Calls: 37

The GCL CPU overload statistics here show that GCL rejected 37 calls as CPU exceeded the 85% busy limit.

Product List

Dialogic IMG 1004 Integrated Media Gateway
Dialogic IMG 1010 Integrated Media Gateway
Dialogic IMG 2020 Integrated Media Gateway (IMG 2020), formerly referred to as Dialogic BorderNet™ 2020 Session Border Controller

Glossary of Acronyms / Terms

GCL - Gateway Control Layer