Asynchronous/Synchronous Serial Module Baud Rates; Eia/Tia-232 Connections; Eia/Tia-449 Connections - Cisco 2600 Series Hardware Installation Manual

Chapter 2 Preparing to Install the Router
Table 2-3
Rate (bps)
2400
4800
9600
19200
38400
56000
1544000 (T1)
Balanced drivers allow EIA/TIA-449 signals to travel greater distances than EIA/TIA-232 signals. The
recommended distance limits for EIA/TIA-449 shown in
EIA-530. Typically, EIA/TIA-449 and EIA-530 can support 2-Mbps rates, and V.35 can support 4-Mbps
rates.

Asynchronous/Synchronous Serial Module Baud Rates

The following baud-rate limitations apply to the slow-speed serial interfaces found in the
asynchronous/synchronous serial modules:
•
•

EIA/TIA-232 Connections

EIA/TIA-232 supports unbalanced circuits at signal speeds up to 64 kbps. The network end of the
adapter cable is a standard 25-pin D-shell connector known as a DB-25. (See
console and auxiliary ports also use EIA/TIA-232 connections; however, the serial module ports support
synchronous connections, and the console and auxiliary ports support asynchronous connections.
Figure 2-1

EIA/TIA-449 Connections

EIA/TIA-449, which supports balanced (EIA/TIA-422) and unbalanced (EIA/TIA-423) transmissions,
is a faster version of EIA/TIA-232 (up to 2 Mbps) that provides more functions and supports
transmissions over greater distances.
OL-2171-02
Serial Signal Transmission Speeds and Distances
EIA/TIA-232
Distance
Feet Meters
200 60
100 30
50 15
25 7.6
12 3.7
8.6 2.6
— —
Asynchronous interface—Maximum baud rate is 115.2 kbps.
Synchronous interface—Maximum baud rate is 128-kbps full duplex.
EIA/TIA-232 Adapter Cable Connectors, Network End
EIA/TIA-449, X.21, V.35,
EIA-530 Distance
Feet Meters
4100 1250
2050 625
1025 312
513 156
256 78
102 31
50 15
Table 2-3
DTE
DCE
Cisco 2600 Series Routers Hardware Installation Guide
Preparing to Connect to a Network
are also valid for V.35, X.21, and
Figure 2-1.) The router
2-9