Nortel Networks 1750 manual System ports, 10/100BASE-TX Ethernet LAN ports

70Appendix A Technical specifications

Table 17 Physical, electrical, and environmental specifications (continued)

Specification	Description
Operating altitude	8202 ft (2500 m) maximum
Storage altitude	40 000 ft (12 192 m) maximum

System ports

This section provides information about the 10/100BASE-TX Ethernet LAN ports and the serial port on the system board.

The VPN Router 1750 system board provides the following built-in interfaces:

•two 10/100BASE-TX Ethernet local area network (LAN) ports

•one serial port

10/100BASE-TX Ethernet LAN ports

The system board provides two 10/100BASE-TX Ethernet LAN interfaces—LAN 0 and LAN 1—on the rear of the chassis. (The LAN 0 interface provides Web management.) Both built-in LAN interfaces accommodate an RJ-45 straight- through cable. Depending on whether you use the interfaces for 10BASE-T or 100BASE-TX operation, select cables for the interfaces as follows:

•100BASE-TX connections require category 5 twisted-pair wire. The 100BASE-TX specification supports 100 Mb/s transmission over two pairs of category 5 twisted-pair Ethernet wiring: one pair each for transmit and receive operations.

Nortel recommends that you use a maximum length of 100 meters for the cable segment between a 100BASE-TX repeater and a workstation (due to signal timing requirements). This wiring scheme complies with the EIA 568 wiring standard.

•10BASE-T connections can use category 3, 4, or 5 twisted-pair wiring.

“10/100BASE-TX Ethernet connector” on page 71 shows the 10/100BASE-TX connector and the connector pinouts.

NN46110-316 03.01