Connecting Cables - Cisco LightStream 2020 Installation Manual

Connecting Cables

Step 3
Step 4
Step 5
Step 6
Note
mode. (See the LightStream 2020 Hardware Reference and Troubleshooting Guide for more detailed
instructions on configuring X.21 ports as DTEs or DCEs.) If you select a DCE interface, note that
you must install a gender converter on each DTE port in order to change the female connector to a
male connector.
Connecting Cables
To connect cables to your LS2020 switch, perform the following steps:
Step 1
Step 2
Step 3
Step 4
2-10 LightStream 2020 Installation Guide
Attach the fantail cable(s) to the back of the fantail and the corresponding access card in
the chassis. (Performing this task now is recommended, rather than installing the fantail
first and having to reach behind it to attach the cable(s) to a connector that you cannot
observe directly.) Note that the cable is reversible; that is, either end of the cable can be
connected to the fantail. Exercise care to avoid suspending the weight of the fantail on the
cable.
Attach the fantail to the rails with the mounting screws and washers provided, using a
slot-tip screwdriver.
Label the fantail with the slot number or the name of the interface module to which the
fantail is connected.
Repeat Step 1 and Steps 3 through 5 to install additional fantails in your LS2020 switch.
If you are mounting an X.21 fantail, set the DTE/DCE switches for each port to the desired
If you have any FDDI cards in your LS2020 switch, install connector keys provided by the
cable vendor onto your FDDI cables. The keys make it impossible to attach a cable to the
wrong kind of connector on the FDDI card.
If you have any OC-3c or FDDI cards in your LS2020 switch, remove and save the
protective covers on the ports that will be used. Leave any unused ports covered.
If you have any E1 CEMAC cards (circuit emulation access cards) in your LS2020 switch,
check the user-settable jumper settings on the card(s). These jumpers allow you to select
termination impedance and grounding on the receive line, as well as the pulse amplitude
and grounding on the transmit line.
As default values, the termination impedance and pulse amplitude jumpers are set to 120
ohms, and the transmit and receive lines are not grounded. Use these default settings if you
plan to use the E1 CEMAC card without a fantail. However, if you do plan to use a fantail
(which provides 75-ohm interfaces), you must use 75-ohm settings for termination
impedance and pulse amplitude and set grounding to on.
For more detailed information about changing the E1 CEMAC card jumper settings,
consult the LightStream 2020 Hardware Reference and Troubleshooting Guide.
Connect any available external data cables. (Refer to the LightStream 2020 Site Planning
and Cabling Guide for details about data cables and connectors.) If you have Ethernet cards
in your LS2020 switch, note that each card supports only eight ports (0 through 7), although
10 physical connectors are available on the access card. Note also that you can use only one
of the 10Base-T or AUI connections on ports 0 and 7.