Cisco BTS 10200 Softswitch, Troubleshooting Manual

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B-17
Cisco BTS 10200 Softswitch Troubleshooting Guide, Release 5.0.x
OL-8723-19
Appendix B System Usage of MGW Keepalive Parameters, Release 5.0
Keepalive for Release 5.0 Prior to Maintenance Release 1.1
Note For TGWs and RGWs with more than 16 endpoints—If a KA attempt is successful, the
system implements
Scenario 1—MGW Reachable regardless of whether there are stable
calls or not.
•
If a KA attempt is unsuccessful: The system raises one or more alarms and continues this pattern of
KA attempts (
Scenario 3—MGW Unreachable ). For any stable calls on this MGW, the system takes
the action specified in the spare1-supp token in the mgw-profile table.
Typical alarms for this condition include:
– SIGNALING (36) —Trunk locally blocked (applicable to CAS, ISDN, and SS7 trunks).
–
SIGNALING (79) —Trunking Gateway unreachable.
– SIGNALING (171) —Residential Gateway unreachable.
Typical informational events for this condition include:
–
SIGNALING (152) —Termination transient error received. This event is applicable when the
keepalive functionality is enabled.
–
SIGNALING (76) —Timeout on remote instance. This event is applicable when the keepalive
functionality is disabled.
• If all KA attempts are unsuccessful through mgcp-keepalive-retries , the system declares the MGW
unreachable.
KA Attempts Unsuccessful, MGW Unreachable, and No Stable Calls Present
This condition is similar to the condition described in “KA Attempts Unsuccessful, MGW Unreachable,
and Stable Call Is Present” section on page B-16 . However, the intervals that occur after the KA attempt
failure are different. This condition, with no stable calls present, is shown in Figure B-12 .
Figure B-12 KA Attempts Unsuccessful, MGW Unreachable, and No Stable Calls Present
KA 1-1 KA 1-2 KA 1- 3 KA 1-4 KA 2-1 KA 3 -1
Interval between KA attempts:
S tarts at 10 seconds and increases
as shown, but is not allowed to exceed
60 seconds (not provisionable).
10 seconds 20 seconds 40 seconds
KA attempt failure – Gateway unreachable.
Occurs if no ACK is received at
any time during this AUEP transaction.
2*mgcp-t-hist
mgcp-keepalive-retries
(default = 3 )
Minimum value is
mgcp-keepalive-interval
(default = 60 seconds).
Maximum value is
mgcp-max-keepalive-interval
(default = 600 seconds).
KA attempts,
all unsuccessful
Time interval (T) with no MGCP
messages when there are no
stable calls, as in
S cenario 2:
Intervals increase by 60 seconds up to
a limit of mgcp-max-keepalive-interval
(default = 600 seconds)
T
T T + 60 T + 120
2500
3
1
Time