
Preparing for Installation 2-17
Network Connection Considerations
Figure 2-15
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 2-16.)
X.21 cables are available as either DTE (DB-15 plug) or DCE (DB-15 receptacle).
Figure 2-16
X.21 Adapter Cable Connectors, Network End
EIA-530 Connections
EIA-530, which supports balanced transmission, provides the increased functionality, speed, and
distance of EIA/TIA-449 on the smaller, DB-25 connector used for EIA/TIA-232, instead of the
37-pin connectors used for EIA/TIA-449. Like EIA/TIA-449, EIA-530 refers to the electrical
specifications of EIA/TIA-422 and EIA/TIA-423. Although the specification recommends a
maximum speed of 2 Mbps, EIA-530 is used successfully at 4 Mbps or faster speeds over short
distances.
The EIA-530 adapter cable is available in DTE mode only. The network end of the EIA-530 adapter
cable is a standard DB-25 plug commonly used for EIA/TIA-232 connections. Figure 2-17 shows
the DB-25 connector at the network end of the adapter cable.
Figure 2-17
EIA-530 Adapter Cable Connector, Network End
H1616a
DTE
DCE
1
8
15
9
DCE
DTE
H1346a
DTE
H1615a
Summary of Contents for Explorer 4700
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Page 132: ...D 6 Cisco 4000 Series Hardware Installation and Maintenance Entering the ROM Monitor Program ...
Page 134: ...E 2 Cisco 4000 Series Hardware Installation and Maintenance For United Kingdom Use Only ...
Page 136: ...F 2 Cisco 4000 Series Hardware Installation and Maintenance For European Community Use Only ...