Cisco BTS 10200 Softswitch, Руководство по устранению неисправностей

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B-32
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 Maintenance Release 1.1 and Later
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-24 for the case with stable call(s) present.
Figure B-24 KA Attempts Unsuccessful, MGW Unreachable, and Stable Call Is Present
Notes for Figure B-24
•
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.
Note
For detailed examples of successful KA attempts, see Figure B-14 and Figure B-15 .
The system takes the following actions in the scenario shown in Figure B-24 :
• If a KA attempt is successful, and stable calls exist: The system implements the KA pattern shown
in Scenario 1. (See
Scenario 1—MGW Reachable .)
KA 1-1 KA 1-2 KA 1- 3 KA 1-4 KA 2-1 KA 3 -1 KA 4-1
allowed to exceed 60 seconds (not provisionable).
Interval between KA attempts: S tarts at 10
seconds and increases as shown, but is not
10 seconds 20 seconds 40 seconds
Time interval with no MGCP
messages, when ther are
stable calls as in
S cenario 1:
mgcp-keepalive-interval
(default = 60 seconds).
Initial KA attempt,
unsuccessful
KA attempt failure – Gateway unreachable.
Occurs if no ACK is received at
any time during this AUEP transaction.
mgcp-keepalive-interval
(default = 60 seconds)
mgcp-keepalive-retries
(default = 3 )
250150
Time
Unsuccessful KA
S uccessful KA
Legend ACK
mgcp-t-max
Completion of mgcp-max2-retries or
expiration of mgcp-t-max, whichever
occurs first. No ACK received.