Cisco BTS 10200 Softswitch, Troubleshooting Manual

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B-10
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
Basic Scenario
The basic scenario is shown in Figure B-5 . The MGW is reachable (an ACK is received during each KA
attempt) and has stable calls, but no MGCP messages have been exchanged between the BTS 10200 and
the MGW for a time interval equal to the provisioned value of
mgcp-keepalive-interval (default 60
seconds) in the mgw-profile table.
Note
The legend in this drawing explains how successful and unsuccessful keepalive attempts are illustrated
throughout this document.
Figure B-5 KA Attempts—MGW Reachable with Stable Calls
Note
For detailed examples of successful KA attempts, see Figure B-1 and Figure B-2 .
The system takes the following actions in the scenario shown in Figure B-5 :
• If KA attempts are successful, and stable calls exist: The system continues this pattern of KA
attempts (
Scenario 1—MGW Reachable ).
•
For RGWs with 16 or fewer endpoints—If KA attempts are successful, and no stable calls exist: The
system implements the KA pattern shown in Scenario 2. (See
Scenario 2 (Special Case)—Reachable
RGW with 16 or Fewer Endpoints and No Stable Calls In Progress .)
Note
For TGWs and RGWs with more than 16 endpoints—If a KA attempt is successful, the
system continues to implement Scenario 1 regardless of whether there are stable calls or not.
•
If a KA attempt is unsuccessful: The system implements the KA pattern shown in Scenario 3. (See
Scenario 3—MGW Unreachable .)
Repeating time intervals with
no MGCP command activity:
mgcp-keepalive-interval
(default = 60 seconds)
KA 1 KA 2 KA 3 KA 4 KA 6 KA 5
250024
Time
Unsuccessful KA
S uccessful KA
Legend ACK
mgcp-t-max 2*mgcp-t-hist