Owner's manual

684 NT8D15 E and M Trunk card

Table 254

DX signaling - incoming calls with originating party release on tandem connections (cont’d.)

Condition

Current in signaling

lead

State of trunk

detector

If no answer supervision: CO end disconnects

(if a CO ground start – the trunk is idled and

network taken down, but the incoming TIE trunk

is held under control of the originating end)

Current flow Low

Originating end disconnects – network taken

down and trunk idled

No current flow High

Duplex (DX) signaling makes use of the voice transmission leads for

signaling as well as for voice transmission. For descriptive purposes, the

lead pair Tip B/Ring B is designated the signaling pair. The other pair Tip

A/Ring A conducts current in the opposite direction to balance the overall

current flow between the near and far ends. During signaling, current flows

through both Tip B and Ring B leads in the same direction.

Figure 231

Signaling orientation for tandem connection between E and M and CO trunks

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311 02.06 Standard

27 August 2008