3-4
Cisco 1900 Series Hardware Installation
OL-19084-01
Chapter 3 Cable Information and Specifications for Cisco 1900 Series Routers
Preparing to Connect to a Network
• Signaling Standards Supported, page 3-4
• Transmission Speeds and Distance Limitations, page 3-5
• Asynchronous/Synchronous Serial Module Baud Rates, page 3-5
About Serial Connections
Serial connections are provided by serial WAN interface cards (WICs). For more information on WICs,
refer to Cisco.com. This document can be accessed online.
Before you connect a device to a serial port, you need to know the following:
• Type of device—data terminal equipment (DTE) or data communications equipment (DCE)—that
you are connecting to the synchronous serial interface
• Type of connector—male or female—that is required for connecting to the device
• Signaling standard that is required by the device
Configuring Serial Connections
The serial ports on the serial WICs use DB-60 connectors. Serial ports can be configured as DTEs or
DCEs, depending on the serial cable used.
Serial DTE or DCE Devices
A device that communicates over a synchronous serial interface is either a DTE or DCE device. A DCE
device provides a clock signal that paces the communications between the device and the router. A DTE
device does not provide a clock signal. DTE devices usually connect to DCE devices. The documentation
for the device should indicate whether it is a DTE or DCE device. (Some devices have a jumper that
allows you to select either DTE mode or DCE mode.) Table 3-1 lists typical DTE and DCE devices.
Signaling Standards Supported
The synchronous serial ports available for the router support the following signaling standards:
EIA/TIA-232, EIA/TIA-449, V.35, X.21, and EIA-530. You can order a Cisco DB-60 shielded serial
transition cable that has the appropriate connector for the standard you specify. The documentation for
the device that you want to connect should indicate the standard used for that device. The router end of
Tab l e 3-1 Typical DTE and DCE Devices
Device Type Gender Typical Devices
DTE Male1
1. If pins protrude from the base of the connector, the connector is male.
• Termi nal
• PC
DCE Female2
2. If the connector has holes to accept pins, the connector is female.
• Modem
• CSU/DSU
• Multiplexer