Nortel Meridian Meridian 1 Feature Description And Administration page 1462

Page 1462 of 1814
Operating parameters
Feature interactions
553-2901-301 Standard 9.00 January 2002
NI-2/QSIG Compliance Update
• ISO QSIG basic call functionality now complies with the North
American standards document, ISO/IEC 115172 second edition.
Initially, support for the ISDN ISO QSIG interface and the basic call
capability was introduced. This version of the interface was based on the
ISO/IEC 115172 first edition document.
• National ISDN-2 (NI-2) basic call functionality now complies with the
latest North American standards document, Bellcore TR-NWT-001268.
The NI-2/QSIG Compliance Update feature changes the way the Meridian 1
handles a recoverable error. Instead of sending incorrect call state
information, the Meridian 1 now sends a correct call state in the STATUS
message.
The mandatory parts of the STATUS message are: CAUSE (indicates type of
error) and CALL STATE. Whenever the Meridian 1 encounters a recoverable
error it sends a STATUS message. Recoverable errors can be cases such as:
• the IE received is non-mandatory and unrecognized
• the IE is non-mandatory and has invalid contents
In cases such as these, the basic call can still be processed, without affecting
basic services, if the call state sent does not hinder this process. All the
protocol must do is report the errors.
Before the protocol compliancy was updated, the Meridian 1 sent the call
state information as it existed before receiving the incoming call message
with the recoverable error. This was not appropriate for other-vendor
switches which dropped the call when the incorrect call state information was
received. Now, the Meridian 1 sends the call state information, adjusted after
the incoming call message was received. The adjusted call state information
allows the other vendor switch to proceed with the basic call.
Fatal errors and errors in non-call-associated messages (such as maintenance
messages) are not affected by this feature. These errors continue to use the
existing error reporting mechanism.
There are no feature interactions specified for this feature.