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ASAI Maintenance Capabilities
Issue 7 May 1998
11-5
Protocol Error (NAK) Cause(s)
None for this capability
Considerations
If the adjunct does not acknowledge a Heartbeat request after sending Resume
Alarms, the ECS restarts the link and generates an alarm, if alarms are
administered.
Restart and Link Versions
Restart provides that either endpoint may use this feature to free and reinitialize
all resources for an ASAI interface. It also insures that if one ASAI endpoint
detects a layer 2 drop [and therefore clears all its CRVs (for example, association)
for the interface], ASAI messaging cannot continue on that interface without the
other endpoint clearing its CRVs also.
Both the ECS and the adjunct initiate the Restart when:
■ An ASAI layer 2 link has been re-established after a link failure.
■ An ECS or adjunct maintenance subsystem determines a need to restart
the ASAI interface.
Link Versions allow an adjunct to negotiate for a specific version of ASAI, as long
as the ECS supports that version. Release 5 supports three versions of ASAI:
version 1, version 2, and version 3.
If a large number of associations are active on the ECS, then the ECS may need
additional time to complete the restart. In this case, the ECS will not acknowledge
(ACK) a received Restart, but will instead send a restart of its own when the data
is initialized and the ECS is ready to bring up the link.
The versions and link restart procedures are covered in the
DEFINITY Enterprise
Communications Server CallVisor ASAI Protocol Reference
, 555-230-221.
Information Flow
This section applies to both the ASAI ISDN BRI and Ethernet links. With ASAI
Versions, the ECS sends a RESTART message to the adjunct containing the
ASAI version(s) offered on the ECS (currently V1, V2 or V3). The adjunct
responds to the ECS’s RESTART message with a Restart Acknowledgement
message that includes the ASAI version of choice for that adjunct. If the ECS does
not support that version, the ECS sends a RESTART message with a list of the
available versions. If the adjunct sends a REstart Acknowledgement message
back with no version, the link is initialized with default version 1. If the adjunct