Reference Manual for the ProSafe VPN Firewall 25 with 4 Gigabit LAN and Dual WAN Ports

Inside Twisted Pair Cables

For two devices to communicate, the transmitter of each device must be connected to the receiver of the other device. The crossover function is usually implemented internally as part of the circuitry in the device. Computers and workstation adapter cards are usually media-dependent interface ports, called MDI or uplink ports. Most repeaters and switch ports are configured as media-dependent interfaces with built-in crossover ports, called MDI-X or normal ports. Auto Uplink technology automatically senses which connection, MDI or MDI-X, is needed and makes the right connection.

Figure B-1illustrates straight-through twisted pair cable.

Figure B-1: Straight-Through Twisted-Pair Cable

Figure B-2illustrates crossover twisted pair cable.

Figure B-2: Crossover Twisted-Pair Cable

Network, Routing, Firewall, and Basics

B-13

202-10085-01, March 2005

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Image 189
NETGEAR FVS124G manual Inside Twisted Pair Cables, Figure B-1illustrates straight-through twisted pair cable