Signaling Standards - Cisco 2500 Series Installation And Configuration Manual

Preparing to Install the Router
Table 2-2: EIA/TIA-232 Speed and Distance
Limitations (Continued)
Data Rate (Baud) Distance (Feet) Distance (Meters)
2400 200
4800 100
9600 50
19200 50
38400 50
64000 25
Balanced drivers allow EIA/TIA-449 signals to travel greater distances than the EIA/TIA-232 signals.
Table 2-3 lists the maximum speeds and distances for EIA/TIA-449, which are also valid for V.35, X.21,
and EIA-530 signals.
Table 2-3: EIA/TIA-449, V.35, X.21, and EIA-530
Speed and Distance
Limitations (Continued)
Data Rate (Baud) Distance (Feet) Distance (Meters)
2400 4,100
4800 2,050
9600 1,025
19200 513
38400 256
56000 102
Caution The EIA/TIA-449 and V.35 interfaces support data rates up to 2.048 Mbps. Exceeding
this maximum could result in loss of data and is not recommended.

Signaling Standards

The synchronous serial port supports the following signaling standards: EIA/TIA-232, EIA/TIA-449,
V.35, X.21, and EIA-530. You can order a DB-60 shielded serial transition cable that has the appropriate
connector for the standard you specify. The router end of the shielded serial transition cable has a DB-60
connector, which connects to the serial port on the rear panel of the router. The other end of the serial
transition cable is available with the connector appropriate for the standard you specify. The
documentation for the device you want to connect should indicate the standard used for that device. The
synchronous serial port can be configured as DTE or DCE (except EIA-530, which is DTE only),
depending on the attached cable.
Note All serial ports configured as DTE require external clocking from a CSU/DSU or other DCE
device.
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60
30
15
15
15
7.6
1,250
625
312
156
78
31