(Page 6 of 6 in this chapter)
Version
isdnStopProtocol
Description
Shuts down a previously started ISDN protocol stack instance and releases all on-board resources and buffers used by the protocol stack instance.
Prototype
DWORD
isdnStopProtocol
(
CTAHD
ctahd
)
ctahd
CTA context handle associated with a D channel, returned by
ctaCreateContext
.
Return Values
SUCCESS
CTAERR_INVALID_CTAHD
The CTA context handle is invalid.
CTAERR_INVALID_STATE
An ISDN protocol stack instance has not been started on the specified CTA context handle, the instance is being started, the instance is already stopped, or the instance is already in the process of stopping.
Events
ISDNEVN_STOP_PROTOCOL
The
value
field of this event contains the completion status of the protocol stopping operation. If the instance stopped successfully, the
value
field contains
SUCCESS
. Otherwise, an error appears here.
Details
Shuts down a previously started ISDN protocol stack instance and releases all HDLC LAPD or Q.931 ACU resources and buffers associated with the instance.
When the ISDN protocol is stopped, the RESTART procedure is initiated. This RESTART procedure implies sending RESTART messages to the remote end (a single RESTART for the entire trunk or one RESTART for each B channel, depending on the variant) and waiting for RESTART ACKNOWLEDGE.
The ISDN stack waits for each RESTART ACKNOWLEDGE message for 20 seconds before declaring the RESTART procedure failed, cleaning its part of the state machine, and continuing the stopping procedure. As a result, if the remote end does not respond (i.e., the RESTART procedure is not implemented or the line is down), the action of stopping the protocols may take more than 20 seconds (up to 8 minutes for variants that do not support RESTART messages for the entire interface).
A behavior bit,
NS_DISABLE_RESTART
, can be used to disable the RESTART procedure in the stack. If this bit is set, the stack does not send RESTART messages when it is stopped, but it also does not respond to incoming RESTART messages. Do not set this bit unless you are certain that the remote end does not implement the RESTART procedure.
For more information about behavior bits, see
Appendix B
.
See Also
isdnStartProtocol
(Page 6 of 6 in this chapter)
Version
Want to send us feedback on our documentation? Email:
Tech_Pubs@nmss.com
Copyright © 2000, Natural MicroSystems, Inc. All rights reserved.
(Page 6 of 6 in this chapter) Version (Page 6 of 6 in this chapter) Version