Cisco CPA2501 User Manual page 135

attachment unit (MAU). The Token Ring port labeled UTP uses an RJ-45 Token Ring cable
and is connected through an adapter or directly to a MAU. Only one Token Ring port can
be used at a time.
Synchronous Serial Connections
The multiport serial routers offer two high-speed synchronous serial ports and from two to
eight (depending on which chassis you have) low-speed asynchronous/synchronous serial
interface ports that can be configured as synchronous serial interfaces.
The high-speed synchronous serial ports are located on the left of the rear panel and are
labeled SERIAL 0 and SERIAL 1.
The serial ports are 60-pin, D-type connectors. All serial interfaces (except the EIA-530)
can be configured as DTE or DCE, depending on the attached cable. The EIA-530 interface
is only configured as DTE. All DTE serial ports require that external clocking be provided
by a channel service unit/data service unit (CSU/DSU) or other DCE device.
You must use a special serial cable to connect a multiport serial router to a modem or
CSU/DSU. This cable is available from Cisco and is usually ordered with the system. The
cable uses a DB-60 connector on the chassis end. See the appendix "Cisco Multiport Router
Cable Specifications" for cable pinouts. For ordering information, contact a customer
service representative.
Note
manufacture your own serial cables is not recommended.
Asynchronous/synchronous Serial Connections
The asynchronous/synchronous serial ports use the asynchronous/synchronous 60-pin
connectors located on the rear panel. The lower ports are labeled SERIAL 2 (A/S) and
SERIAL 3 (A/S): the upper ports (depending on which chassis you have) are labeled
SERIAL 4 (A/S) through SERIAL 9 (A/S).
Because of the small size of the pins on the DB-60 serial connector, attempting to
Preparing to Install the Cisco Multiport Serial Routers 2-13
Network Connection Considerations