1 for copper ethernet ports, including 10/100 ports, 10/100/1000 ports, and 1000base-t sfp module ports, cable lengths from the switch to connected devices can be up to 328 feet (100 meters).
2 table 2-1 lists the cable specifications for 1000base-sx, 1000base-lx, 1000base-zx, and 100base-fx fiber-optic sfp module connections. each port must match the wave-length specifications on the other end of the cable, and for reliable communications, the cable must not exceed the required cable length.
1. a mode-conditioning patch cord is required. using an ordinary patch cord with mmf, 1000base-lx/lh sfp modules, and a short link distance can cause transceiver saturation, resulting in an elevated bit error rate (ber). when using the lx/lh sfp module with 62.5-micron diameter mmf, you must also install a mode-conditioning patch cord between the sfp module and the mmf cable on both the sending and receiving ends of the link. the mode-conditioning patch cord is required for link distances greater than 984 feet (300 m).
2. 1000base-zx sfp modules can send data up to 62 miles (100 km) by using dispersion-shifted smf or low-attenuation smf; the distance depends on the fiber quality, the number of splices, and the connectors.
when using shorter distances of single-mode fiber cable, you might need to insert an inline optical attenuator in the link to avoid overloading the receiver.
when the fiber-optic cable span is less than15.43 miles (25 km), you should insert a 5-decibel (db) or 10-db inline optical attenuator between the fiber-optic cable plant and the receiving port on the 1000base-zx sfp module at each end of the link.
1 operating environment is within the ranges listed in appendix a, “technical specifications.”
2 clearance to front and rear panels is such that
1.front-panel indicators can be easily read.
2.access to ports is sufficient for unrestricted cabling.
3.rear-panel power connector is within reach of an ac power receptacle.
3 cabling is away from sources of electrical noise, such as radios, power lines, and fluorescent lighting fixtures. make sure the cabling is safely away from other devices that might damage the cables.
4 airflow around the switch and through the vents is unrestricted.
5 temperature around the unit does not exceed 113℉(45℃).
if the switch is installed in a closed or multirack assembly, the temperature around it might be greater than normal room temperature.