Juniper Networks E-Series - Manual (Page 183)

I/O Module Specifications
E-Series Routers
12-39
Cable Lengths for X.21/V.35 Cables
Serial signals can travel a limited distance without significant
degradation. Slower serial signals can travel farther without degradation
than faster serial signals.
Table 12-4 shows the maximum cable lengths
you can use to prevent signal degradation at various transmission speeds.
Table 12-4 Maximum cable lengths for X.21/V.35 connections
Transmission
Speed (Hz)
Cable Length
(Feet)
Cable Length
(m)
2400 4,100 1,250
4800 2,050 625
9600 1,025 312
19200 513 156
38400 256 78
56000 102 31
2048000 25 8