connector can be male for DTE or female for DCE. To order a cable, see
Obtaining Technical Assistance,
on page xi
.
Figure 26: V.35 Adapter Cable Connectors, Network End
X.21 Connections
The X.21 connector uses a 15-pin connector for balanced circuits, and is commonly used in the United Kingdom
to connect to the public data network. 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.
Use the X.21 serial transition cable (not included with...) the Cisco 12-in-1 connector on one end and a DB-15
connector on the other (Figure 27). The DB-15 connector can be male for DTE or female for DCE. To order
a cable, see
Obtaining Technical Assistance, on page xi
.
Figure 27: X.21 Adapter Cable Connectors, Network End
EIA/TIA-530 Connections
The EIA/TIA-530 standard, which supports balanced transmission, provides increased functionality, speed,
and distance of EIA/TIA-449 on the smaller DB-25 connector used for EIA/TIA-232. Like EIA/TIA-449,
EIA/TIA-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/TIA-530 is used successfully at 4 Mbps or faster
speeds over short distances. The Cisco VG310 and Cisco VG320 Analog Voice Gateways support speeds up
to 2.048 Mbps.
Cisco VG310 and Cisco VG320 Voice Gateways Hardware Installation Guide
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Cable Specifications and Information
X.21 Connections
