Instruction manual

Traveling class marks
Issue 4 May 2003 163555-233-767
Traveling class marks
Traveling Class Marks are a mechanism for passing a caller’s facility restriction
level from one Electronic Tandem Network switch to another. Traveling Class
Marks allow privilege checking to be passed across switches through the
Electronic Tandem Network.
Miscellaneous
Answer detection
For purposes of Call-Detail Recording (CDR), it is important to know when the
called party answers a call. Communication Manager provides three ways to
determine whether the called party has answered an outgoing call.
Answer supervision by time-out
You set a timer for each trunk group. If the caller is off-hook when the timer
expires, Communication Manager assumes that the call has been answered. This
is the least accurate method. Calls that are shorter than the timer duration do not
generate call records, and calls that ring for a long time produce call records
whether they are answered or not.
Call-classifier board
A call-classifier board detects tones and voice-frequency signals on the line and
determines whether a call has been answered.
Network answer supervision
The Central Office (CO) sends back a signal to indicate that the far end has
answered. If a call has traveled over a private network before reaching the CO, the
signal is transmitted back over the private network to the originating system. This
method is extremely accurate, but is not available in the United States over CO,
FX, or WATS trunks.