Lucent Technologies DEFINITY Enterprise Communications Server Release 5, CallVisor, ASAI Protocol Reference Instructions Manual

Ending an ASAI Association
Issue 6  June 1997
2-55
Rejects an Invalid/Protocol Violation FIE — Terminates Association’’ on page 
5-68 of Chapter 5, “Byte Level Messages.” For domain control coding, see 
‘‘Domain Control: Endpoint Rejects an Invalid/Protocol Violation FIE — 
Terminates Association’’ on page 5-96 of Chapter 5, “Byte Level Messages.”
The ECS does not attempt to retry during any association where an adjunct 
rejects an FIE that the ECS has sent. If the ECS receives a Reject component in a...

Messaging Sequences and ASAI
2-56Issue 6  June 1997 
nThe ECS checks to make sure that in-use and available CRVs are used 
appropriately in ASAI messages. If the ECS receives:
1. A REGister message containing a CRV that is already in use on the 
ASAI for another association, then the ECS responds with a 
RELease COMplete message containing Cause CS0/81, “Invalid 
CRV.” This message does not contain an FIE.
2. A FACility message containing an idle CRV, then the ECS responds 
with a RELease COMplete...

Link Management and Maintenance Procedures
Issue 6  June 1997
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nIf a field within an IE contains an invalid, reserved, or unrecognized code 
point, the ECS returns CS0/100, “Invalid IE Contents.”
Link Management and Maintenance 
Procedures
Maintenance procedures use additional messages beyond the REGister, FACility, 
and RELease COMplete messages that carry capability invocations discussed 
previously. These ISDN messages (RESTart, RESTart ACKnowledge) provide 
additional procedures to keep the ECS...

Messaging Sequences and ASAI
2-58Issue 6  June 1997 
ASAI Restart Procedure
Both the ECS and adjunct must adhere to the Restart Procedure on an ASAI 
link.21 The Restart Procedure insures that if one ASAI endpoint detects a layer 2 
drop (and therefore clears all its CRVs for the interface), ASAI messaging cannot 
continue on that interface without the other endpoint clearing its CRVs, also.
22 
Both ECS and adjunct begin the Restart Procedure when:
nAn ASAI has been established at layer 2.
nAn ASAI...

Link Management and Maintenance Procedures
Issue 6  June 1997
2-59
nThe RESTART message MUST NOT contain the optional Channel 
Identifier IE. The absence of this IE indicates that the interface is to be 
restarted. Since a Channel Identification IE is present in a BRI RESTart 
message only to restart a specific B-channel [see the 
ISDN Basic Rate 
Interface (BRI) Specification
], this information element is not applicable to 
the ASAI. The ECS ignores the Channel Identification IE if it is present.
nThe...

Messaging Sequences and ASAI
2-60Issue 6  June 1997 
expected response is a REST ACK either with no version IEs or with a version IE 
indicating one of the available versions. Any other response causes the ECS to 
log a maintenance error.
Suspend/Resume ECS Alarming on ASAI Link
These procedures let an adjunct:
nSuspend any ECS alarming in effect for an ASAI link when the adjunct 
takes the link out of service for scheduled maintenance or for graceful 
termination of the link for some other reason....

Application Timers
Issue 6  June 1997
2-61
Application Timers
Timing of ASAI Responses (ACKs/NAKs)
The ASAI specification does not contain timers for situations where message loss 
results in an application waiting infinitely for the message from the other endpoint. 
Rather, ASAI applications are required to set timers when they make requests. If 
the timer expires and the application has not received a response, the application 
must abort the association, and it may retry if it desires.
Certain adjunct...

Messaging Sequences and ASAI
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Issue 6 June 19973-1
3
Message Descriptions
This chapter details the ASAI messages introduced in Chapter 1.
Message Overview
ASAI is based on standard protocols, including CCITT Recommendations Q.931 
and Q.932, and the 
ISDN Basic Rate (BRI) Interface Specification, 803-802-100. 
These protocols contain such information as allowable message types and 
required format, which ASAI follows.
Table 3-1 lists the ASAI message types described in this chapter.
Table 3-1. Messages for ASAI
ASAI Message
FACility...

Message Descriptions
3-2Issue 6 June 1997 
Each explanation includes:
nA brief description of the message direction and use
nA table listing the information elements contained in the message. For each 
information element, the table indicates:
— The direction in which the information element may be sent; for 
example, adjunct-to-ECS, ECS-to-adjunct, or both. (All information 
elements for these messages are “both.”)
— Whether the information element is mandatory (M) or optional (O).
— The allowed length,...