Installation guide

4-64 Cisco 4000 Series Installation Guide
Network Connection Considerations
V.35 Connections
The V.35 interface is recommended for speeds up to 48 kbps, although in practice it is used
successfully at 4 Mbps.
The network end of the V.35 adapter cable provides a standard 34-pin Winchester-type
connector. (See Figure 4-16.) V.35 cables are available with a standard V.35 plug or
receptacle in either DTE or DCE mode.
Figure 4-16 V.35 Adapter Cable Connectors, Network End
X.21 Connections
The X.21 interface uses a 15-pin connection for balanced circuits and is commonly used in
the United Kingdom to connect public data networks. X.21 relocates some of the logic
functions to the DTE and DCE interfaces and, as a result, requires fewer circuits and a
smaller connector than EIA/TIA-232.
The network end of the X.21 adapter cable is a standard DB-15 connector.
(See Figure 4-17.) X.21 cables are available as either DTE (DB-15 plug) or DCE (DB-15
receptacle).
H1616a
DTE
DCE