Nortel Networks 2700 manual Appendix a Technical specifications 21 cable pinouts

Appendix A Technical specifications 99

Table 33 X.21 cable pinouts (continued)

Standard-wired		Pair number	Standard-wired
end 28-pin male	Signal name	and conductor	end 15-pin male	Notes
5	CTSA	pair 7A	5
13	CTSB	pair 7B	12
6	DSRA	pair 8A	no conn	Note 2
22	DSRB	pair 8B	no conn	Note 2
20	DTRA	pair 9A	no conn	Note 2
23	DTRB	pair 9B	no conn	Note 2
8	DCDA	pair 10A	no conn	Note 2
10	DCDB	pair 10B	no conn	Note 2
18	LL	pair 11A	no conn	Note 2
21	RL	pair 11B	no conn	Note 2
25	TM	pair 12A	no conn	Note 2
26	M0	pair 12B	no conn	Note 2
27	M1	pair 13A	no conn	Note 2
28	M2<-SIGNAL GROUND	pair 13B	8	Note 3
1	SHIELD	pair 14A	1	Note 4,5
7	SIGNAL GROUND	pair 14B	8	Note 3,5

The following notes apply to the single X.21 cable:

1.Wires of pair 4 connect to wires of pair 5, but not to any pins in the DA-15.

2.The term “no conn” means the wire is not connected to a pin in the 15-pin connector.

3.Wires 13B and 14B connect to pin 8 in the 15-pin connector.

4.At each end, the cable shield and connector shell must connect to pin 1 of the connector.

5.Do not interconnect Shield to Signal Ground because these are separate signals.

Nortel VPN Router Installation — VPN Router 2700