B-21
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
Initial Transmission Waiting Period (mgcp-t-tran)
The initial transmission waiting period (the period that the system waits after sending an initial AUEP
transmission before repeating it) is equal to
the greater of
the following:
•
The average response time between the sending of an MGCP message, and receiving a response.
•
A specified lower limit, provisioned as
mgcp-t-tran
(default 400 milliseconds) in the
mgw-profile
table.
In a typical network, the average response time is much less than 400 milliseconds. Therefore, in this
section, the drawings show the initial waiting period as
mgcp-t-tran
.
Note
The drawings in this section are not to scale.
Scenarios with AUEP Message Retransmissions and ACK Received
is applicable when one IP address is provisioned for the MGW in the DNS server. It
illustrates the scenario in which the initial AUEP transmission does not receive an ACK message, but an
ACK is received in response to retransmissions.
Figure B-14
One IP Address in DNS, ACK Received after Retransmissions
Note
See the additional information about
mgcp-t-tran
in the
“Initial Transmission Waiting Period
(mgcp-t-tran)” section on page B-21
Time
AUEP, initial
transmission
ACK
received
trying 1st IP address
mgcp-t-tran
2*mgcp-t-tran
4*mgcp-t-tran
8
*mgcp-t-tran
KA attempt
(AUEP transaction),
successful
mgcp-max2-retries,
for 1st IP address
(default =
3
)
AUEP,
2nd transmission
(1st retransmission)
AUEP,
3
rd transmission
(2nd retransmission)
AUEP,
4th transmission
(
3
rd retransmission)
250020
