Performance Droop On 200 Mb/S Links - EMC Connectrix EC-1200 Planning Manual

200 MB/s
150 MB/s
100 MB/s
50 MB/s
0 MB/s
4 km 8 km
Figure 4-10
Distance Topology
16 km 32 km 48 km
Distance

Performance Droop on 200 MB/s Links

Most Fibre Channel equipment is designed for shortwave lasers with
multimode optical fibers, which is effective for up to 500 meters.
Greater distances can be achieved using longwave lasers with
single-mode fiber.
The Fibre Channel specification for 2 Gb/s shortens the allowed
distance for multimode fiber cables. For multimode runs that exceed
the distance limits in the table below, use the speed control
mechanism, in Connectrix Manager or the EWS to throttle the speed
to 1 Gb/s. This will prevent 2 Gb/s autonegotiation from occuring
over an unsupported distance.
Multimode Distance Limits in Meters
50/125
1 Gb/sec 500
2 Gb/sec 300
Greater distances require two fabric switches connected with
longwave lasers over 9/125 single-mode fiber cable.
To achieve the distances, a special optics module is installed in the
ED-64M and ED-140M. This module can be used for distances up to
10 kilometers. Refer to the Connectrix ED-64M Director User Guide or
the Connectrix ED-140M Director User Guide for more detail.
The 10 km capability is dependent on the quality of the fiber cable
between the two data centers. When deploying any length of
64 km 80 km 96 km 112 km 120 km
62.5/125
300
150
Multiswitch Topologies
Connectrix Topologies
60 BB_Credits
16 BB_Credits
8 BB_Credits
2 BB_Credits
4-13
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