Nortel 1750, Install Manual

Page: 97 / 108

Appendix A Technical specifications
97
Nortel VPN Router Installation — VPN Router 1750
Single V.35/X.21 WAN interface card
The single V.35/X.21 WAN interface card has a single DB28S connector that
provides the signals needed to interface to V.35 and X.21 equipment.
Figure 43
shows the single V.35/X.21 WAN interface card.
Figure 43
Single V.35/X.21 WAN interface card
You need a DSU/CSU (digital service unit/channel service unit) between the
WAN connection and the gateway. You can order a V.35 or X.21 cable to attach to
the connector. With this cable, the WAN adapter can function as DTE (data
terminal equipment).
Table 32 provides the V.35 cable pinouts. Table 33 on page 99 provides the X.21
cable pinouts. (The pair suffix A or B refers to an individual wire within a twisted
pair.)
3 Ring
4 N/C
Table 32
V.35 cable pinouts
Standard-wired
end 28-pin male Signal name
Pair number
and conductor Special-wired
end 34-pin male Notes
2 TXDA pair 1A P
14 TXDB pair 1B S
3 RXDA pair 2A R
16 RXDB pair 2B T
15 TXCA pair 3A Y
12 TXCB pair 3B AA
Table 31
MV.90 modem cable pinouts (continued)
Pin Function
CS160011A