Nortel DMS-100 Series Maintenance Manual page 51

Subscriber A calls subscriber B and establishes a speech path.
Subscriber A has the call waiting (CWT) line service option. A third
party dials subscriber A. Subscriber A receives information about the
waiting call. A controlled Warm SWACT occurs on the SMS that
connects to subscriber A. When subscriber A attempts to place
subscriber B on hold to access the waiting call, the system ignores the
hook flash. The speech path between subscribers A and B remains.
On calls that originate from a coin telephone the call is not always
maintained during a warm SWACT. Heavy traffic or no answer at the
terminating end can prevent the maintenance of a call during a warm
SWACT. If this event occurs the coin is not returned or collected. The
coin remains in the hopper. The calling-party receives a dial tone and
can redial the call. If the calling-party presses the switch hook, the coin
telephone returns the coin.
The system maintains timing for a billing call when a Warm SWACT
occurs.
The system deactivates the enhanced Warm SWACT feature when an
unsupported subscriber feature is active over the Warm SWACT. The
nonenhanced Warm SWACT handling is the default to handle the call
when unsupported subscriber features are present. The system ignores
hook flashes. Far-end changes are taken down the call. The system
ignores conference key messages and transfer key messages. The system
ignores call park key messages, and busy override key messages from a
business set.
A SWACT can occur when a subscriber line test is in progress. An RCS
creates a connection to the metallic test pair. When a SWACT occurs, the
current test fails. Operating company personnel can release the connection
to the metallic test pair, access the test network again, and retry the test.
Warm SWACT and the SWACT back feature
The XPM Pre-SWACT/Post-SWACT Audit, feature AF5007, improves the
Warm SWACT operation. Feature AF5007 denies the SWACT if the
inactive unit cannot maintain activity or communication with the CM.
Under these conditions, this feature can SWACT back to the original active
unit. The software that drives this feature is the SWACT controller.
The system routes all manual requests and selected system requests for
SWACTs to the SWACT controller in the CM. The SWACT controller polls
PM diagnostic history data in the CM and XPM state data. Do not confuse
the CM and XPM state data with XPM static data. The SWACT controller
denies the request for a Warm SWACT or allows a Warm SWACT to
proceed. The data polled determines the actions of the SWACT controller.
DMS-100 Family SMS Maintenance Manual XPM10 and up
Maintenance overview 1-35