3Com Router 3012, Installation Manual

Page: 29 / 72

Connecting the Router to the WAN 29
In general, the asynchronous serial interface is connected to a modem or a
terminal adapter (TA) to act as the dial-up interface. In this case, it is unnecessary
to determine whether the device is DTE or DCE, you must only select the
appropriate baud rate.
The synchronous/asynchronous serial interface cable is connected to a DB-50
receptacle. Proper connection cable needs to be selected for the protocol applied.
Nine types of synchronous/asynchronous serial interface cables are available.
However, these cables are optional and you must select the proper one based on
your requirements when you purchase the router All these types of cables have a
DB-50 adapter at the router end.
At the network end, the connector is different for each type of cable, as described
in the following list:
■
V.24 (EIA/TIA-232) DTE cable — DB-25 (male) adapter
■
V.24 (EIA/TIA-232) DCE cable — DB-25 (female) adapter
■
V.35 DTE cable — 34-pin (male) adapter
■
V.35 DCE cable — 34-pin (female) adapter
■
X.21 DTE cable — DB15 (male) adapter
■
X.21 DCE cable — DB15 (female) adapter
■
EIA/TIA-449 DTE cable — DB37 (male) adapter
■
EIA/TIA-449 DCE cable — DB37 (female) adapter
■
EIA-530 DTE cable — DB25 (male) adapter
For the pinouts of these cables, see Appendix A.
The following figures show the assembly of all 9 cable types:
■
V.24 DTE Cable Assembly
■
V.24 DCE Cable Assembly
■
V.35 DTE Cable Assembly
■
V.35 DCE Cable Assembly
■
X.21 DTE Cable Assembly
■
X.21 DCE Cable Assembly
■
EIA/TIA-449 DTE Cable Assembly
■
EIA/TIA-449 DCE Cable Assembly
■
EIA-530 DTE Cable Assembly
DTE male PC or router
DCE female Modem, multiplexer or CSU/DSU