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CEPT transceiver
Slip control
D-channel support interface
553-3011-100
Standard 14.00
NTAK79 2.0 Mb PRI card
The transmitter and receiver functions are used for synchronization, channel,
and signal extraction. The functions meet applicable specifications of the
CCITT recommendation G.703 & G.732.
The transceiver provides transmit framing based on the 2.048 MHz clock
derived from the DS-30X system clock and 1KHZ framing pulse.
Slip control provides organized recovery of PCM when the clock recovered
from the external facility is at a different frequency with respect to the local
clock.
The D-channel support interface is a 64 kbps, full-duplex serial bit stream
configured as a DCE device. The data signals include: (1) Receive data
output, (2) transmit data input, (3) receive clock output, and (4) transmit clock
output. The receive and transmit clocks can be of slightly different bit rates
from each other as determined by the transmit and receive carrier clocks.
The NTAK79 has an onboard D-channel handler interface (DCHI). It is the
equivalent to a single port of an NTAK02 SDI/DCH pack. This allows for a
completely operational ISDN PRA link with clock synchronization and D-
channel on a single circuit card.
The onboard D-channel has one status LED on the NTAK79 faceplate to
indicate enabled/disabled states. (See Table 148).
The on-board DCHI can be operated in two separate modes as defined by an
on-board dip switch. It can operate in a standard DCHI mode common to
most ISDN standard countries. It can also operate in an U.K. specific mode
using the DPNSS format.
January 2002
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