Cisco BTS 10200 Troubleshooting Manual page 824

Keepalive for Release 5.0 Prior to Maintenance Release 1.1
KA Attempts Unsuccessful, MGW Unreachable, and Stable Call Is Present
If no ACK is received during any KA attempt, and no MGCP messages have been exchanged between
the BTS 10200 and the MGW for a specified time interval (see the time interval description in the
drawing), the system performs a specified number of KA retries before declaring the MGW to be
unreachable. This condition is shown in
Figure B-11 KA Attempts Unsuccessful, MGW Unreachable, and Stable Call Is Present
Initial KA attempt,
unsuccessful
KA 1-1
Time interval with no MGCP
messages, when ther are
stable calls as in Scenario 1:
mgcp-keepalive-interval
(default = 60 seconds).
Interval between KA attempts: Starts at 10
seconds and increases as shown, but is not
allowed to exceed 60 seconds (not provisionable).
Notes for
•
•
•
For detailed examples of successful KA attempts, see
Note
The system takes the following actions in the scenario shown in
•
•
Cisco BTS 10200 Softswitch Troubleshooting Guide, Release 5.0.x
B-16
2*mgcp-t-hist
KA 1-2 KA 1-3
10 seconds 20 seconds 40 seconds
Figure B-11
The keepalive attempts labeled KA 1-2, KA 1-3, and KA 1-4 represent retries of the original
keepalive attempt KA 1-1. The number of retries is provisioned as mgcp-keepalive-retries.
The keepalive attempts labeled KA 2-1, KA 3-1, and further, represent new attempts spaced
according to the provisioned value of mgcp-keepalive-interval.
Each keepalive attempt, KA 1-1, KA 1-2, ... KA 2-1, KA 3-1, and further, has a unique MGCP
transaction ID.
If a KA attempt is successful, and stable calls exist: The system implements the KA pattern shown
in Scenario 1. (See Scenario 1—MGW
For RGWs with 16 or fewer endpoints—If a KA attempt is successful, and no stable calls exist: The
system implements the KA pattern shown in Scenario 2. (See
RGW with 16 or Fewer Endpoints and No Stable Calls In
Appendix B System Usage of MGW Keepalive Parameters, Release 5.0
Figure B-11 for the case with stable call(s) present.
mgcp-keepalive-retries
(default = 3)
KA 1-4 KA 2-1
mgcp-keepalive-interval
(default = 60 seconds)
KA attempt failure – Gateway unreachable.
Occurs if no ACK is received at
any time during this AUEP transaction.
Legend
Successful KA
Unsuccessful KA
Figure B-1
Reachable.)
KA 3-1 KA 4-1
ACK
mgcp-t-max 2*mgcp-t-hist
and Figure B-2.
Figure B-24:
Scenario 2 (Special Case)—Reachable
Progress.)
Time
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