Appendix B      Connectors and Cables
Connector Specifications
B-4
Catalyst 2950 Desktop Switch Hardware Installation Guide
78-11157-05
Connecting to 10BASE-T and 100BASE-TX Devices
When connecting the ports to 10BASE-T and 100BASE-TX devices, such as 
servers, workstations, and routers, you can use a two or four twisted-pair, 
straight-through cable wired for 10BASE-T and100BASE-TX. Figure B-8 shows 
the two twisted-pair, straight-through cable schematics. Figure B-10 shows the 
four twisted-pair, straight-through cable schematics.
When connecting the ports to 10BASE-T- and 100BASE-TX devices, such as 
switches or repeaters, you can use a two or four twisted-pair, crossover cable. 
Figure B-9 shows the two twisted-pair, crossover cable schematics. Figure B-11 
shows the four twisted-pair, crossover cable schematics.
You can use Category 3, 4, or 5 cabling when connecting to 10BASE-T devices. 
You must use Category 5 cabling when connecting to 100BASE-TX devices.
Connecting to 1000BASE-T Devices
When connecting the ports to 1000BASE-T devices, such as servers, 
workstations, and routers, you must use a four twisted-pair, Category 5, 
straight-through cable wired for 10BASE-T, 100BASE-TX, and 1000BASE-T. 
Figure B-12 shows the straight-through cable schematics. 
When connecting the ports to other devices, such as switches or repeaters, you 
must use a four twisted-pair, Category 5, crossover cable. Figure B-13 shows the 
crossover cable schematics.
Note Be sure to use a four twisted-pair, Category 5 cable when connecting to a 
1000BASE-T device.
Note Use a straight-through cable to connect two ports only when one port is 
designated with an X. Use a crossover cable to connect two ports when both ports 
are designated with an X or when both ports do not have an X.