Cisco Systems 1900 Series manual About Serial Connections, Configuring Serial Connections

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 3-1lists typical DTE and DCE devices.

Table 3-1	Typical DTE and DCE Devices
Device Type		Gender	Typical Devices
DTE		Male1	•	Terminal
			•	PC
DCE		Female2	•	Modem
			•	CSU/DSU
			•	Multiplexer

1.If pins protrude from the base of the connector, the connector is male.

2.If the connector has holes to accept pins, the connector is female.

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

Cisco 1900 Series Hardware Installation

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