Cisco LightStream 1010 Configuration Note page 9

Preparing Network Connections
When preparing your site for network connections to the switch, you need to consider a number of
factors related to each type of interface:
•
Type of cabling required for each type (fiber, twisted-pair, or coaxial cabling).
•
Distance limitations for each signal type.
•
Specific cables you need to connect each interface.
•
Any additional interface equipment you need, such as transceivers, modems, channel service
units (CSUs), or data service units (DSUs). Before installing the switch, have all additional
external equipment and cables on hand. If you intend to build your own cables, refer to the cable
pinouts in the section "Installing the LightStream 1010 Switch" in the LightStream 1010 ATM
Switch User Guide publication. For ordering information, contact a customer service
representative.
Distance Limitations
The length of your networks and the distances between connections depend on the type of signal,
the signal speed, and the transmission media (the type of cabling used to transmit the signals). For
example, fiber-optic cable has a greater channel capacity than twisted-pair cabling. The following
distance limits are provided as guidelines for planning your network connections before installation.
Serial Connections
Serial signals can travel a limited distance at any given bit rate; generally, the slower the baud rate,
the greater the distance. Table 5 shows the standard relationship between baud rate and distance for
EIA/TIA-232 signals.
Table 5
Rate (bps)
2400
4800
9600
19200
38400
56000
Additional and Optional Connection Equipment
To install and configure the switch, you need a terminal with an EIA/TIA-232 data terminal
equipment (DTE) port and an EIA/TIA-232 data communications equipment (DCE) console cable
with DB-25 plugs at one end. You can detach the terminal (and cable) after the installation and
configuration procedures are complete.
IEEE Standard EIA/TIA-232 Transmission Speed Versus Distance
Distance (feet) Distance (meters)
200 60
100 30
50 15
25 7.6
12 3.7
8.6 2.6
LightStream 1010 ATM Switch Processor Module Configuration Note
Preparing Network Connections
9