Nortel Networks NN43001-301 manual Channel and Msdl interface

58ISDN Primary Rate Interface equipment overview

D-Channel and MSDL interface

The connection between the DDP card and the DCHI or MSDL is via a 26 pin female D type connector. The data signals conform to the electrical characteristics of the EIA standard RS-422.

Two control signals are used to communicate the D-Channel link status to the DCHI or MSDL. These are:

•Receiver Ready (RR), originating at the DDP card, to indicate to the DCHI or MSDL that the D-channel link is operational.

•Transmitter Ready (TR), originating at the DCHI or MSDL, to indicate to the DDP card that the DCHI or MSDL are ready to use the D-Channel link.

Table 15 "DCHI/MSDL Receiver Ready control signals" (page 58) indicates how the RR control signal operates with regard to the DDP status.

Table 15

DCHI/MSDL Receiver Ready control signals

RR State	Condition
ON	D-Channel data rate selected at 64 Kbps or 56 Kbps or 64 Kbps
	inverted
	and
	PRI loop is enabled
	and
	PRI link is not in RED alarm mode state
	and
	PRI link is not transmitting a yellow alarm pattern
	and
	PRI link is not receiving a Remote Alarm Indication from the
	remote facility
	and
	PRI link is not in FA3 mode

Nortel Communication Server 1000

ISDN Primary Rate Interface Installation and Commissioning

NN43001-301 02.03 Standard

Release 5.5 7 December 2007

Copyright © 2003-2007, Nortel Networks