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Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (H.323)
OL-4008-01
Chapter4 Basic and Additional H.323 Services
Important Basic H.323 Services
If LoginID1 and LoginID2 are not used or are not set to identical values, the Cisco ATA uses
dual-registration mode.
Related Parameters
•LoginID0, page 5-13
•LoginID1, page 5-14
•UID0, page 5-10
•UID1, page 5-11
Setting Up Gatekeeper Time-To-Live Value
You can specify the valid duration of the H.323 gatekeeper registration, in seconds, by using the
GkTimeToLive parameter.
Related Configuration Parameter
GkTimeToLive, page 5-17
Setting Up an Alternate H.323 Gatekeeper
To provide redundancy in systems that use an H.323 gatekeeper, the Cisco ATA allows you to either
statically configure an alternate H.323 gatekeeper or dynamically assign an H.323 ga tekeeper.
To enable the static alternate gatekeeper feature, you need to configure the AltGk parameter with the IP
address assigned to the alternate H.323 gatekeeper. To enable the CiscoATA to perform full gatekeeper
registration when it switches to a statically configured alternate H.323 gatekeeper, configure Bit 3 of the
ConnectMode parameter to the value of 1.
To enable the dynamic alternate gatekeeper feature, you need to configure the primary H .323 gatekeeper
so that the list of alternate gatekeepers is included in the H.225 RAS messages that the H.323 gatekeeper
sends to the CiscoATA. The Cisco ATA can accept as many as four dynamic alternate gatekeepers
configured in the H.225 RAS messages. (The Cisco ATA supports the alternate gatekeeper list in
GCF/GRJ, ACF/ARJ, RCF/RRJ, and DRJ RAS messages.)
Dynamic alternate gatekeepers and static alternate gatekeepers can co-exist. When the CiscoATA
receives an alternate gatekeeper list in an H.225 RAS message, the static alternate gatekeeper is merged
with the dynamic alternate gatekeepers. The static alternate gatekeeper is kept and given the lowest
priority.
You can configure the AltGkTimeout parameter to specify the number of seconds the Cisco ATA should
wait before it automatically switches back to the primary H.323 gatekeeper after being moved to an
alternate gatekeeper. By default, the switch-back procedure is disabled (the AltGkTimeout parameter
value is set to 0).
Related Configuration Parameters
•AltGk, page 5-16
•AltGkTimeOut, page 5-16
•ConnectMode, page 5-28