Functional description 319
System software then sends the CND information to the CLASS Modem
card, one byte at a time, where it is stored in the message buffer. If the
CLASS Modem card receives more bytes than were specified in the
initiating message, then the additional bytes are discarded and not included
in the CND memory buffer.
Once all of the CND information has been stored in the memory buffer, the
CLASS Modem card begins transmission when requested by the system
software. Data is sent one ASCII character at a time. The CLASS Modem
card inserts a start and stop bit to each ASCII character sent.
The transmission of the calling party name/number to the terminating
telephone is accomplished through asynchronous FSK simplex-mode
transmission at 1200 bits/second over a 2-wire loop, in accordance with the
Bell 202 standard. The transmission is implemented by the appropriate
PCM equivalent of 1200 or 2200 Hz.
Upon completion of transmitting the CND data, the CLASS Modem card
sends a message to the system softwareto indicate successfultransmission
of the CND data.
Eight modems can be associated with each module. Table 128 "Time slot
mapping" (page 319) shows time slot mapping for the CLASS modem card.
Table128
Time slot mapping
XCMC mapping of TNs
TNs DS30X
timeslot Modem units on the CLASS
Modem card
00
01
02
03
00
01
02
03
module 0, 00
01
02
03
04
05
06
07
04
05
06
07
04
05
06
07
08
09
10
11
08
09
10
11
module 1,
00
01
02
03
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23May 2008
Copyright© 2003-2008, Nor tel Networks
.