Server User's Manual

58 ISDN Primar y 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