Cisco 3825 Hardware Installation Guide - Page 103

CH A P T E R 5 Connecting Serial Network Modules This chapter describes how to connect serial network modules for Cisco modular routers and contains the following sections: • About Serial Connections, page 5-1 • Connecting Asynchronous Network Modules to Asynchronous Devices, page 5-4 • Asynchronous Network Module Interface Numbering, page 5-6 • 4-Port Serial Network Module, page 5-9 • 16- and 32-Port Asynchronous Serial Network Modules, page 5-11 • 4-, 8-, and 16-Port Asynchronous/Synchronous Serial Network Modules, page 5-12 Tip To determine whether your router supports a specific network module, see Table 1-6 on page 1-16. About Serial Connections Serial connections can be provided by either WAN interface cards or network modules. For more information about WAN interface cards, see the Cisco Interface Cards Hardware Installation Guide. To obtain this publication, see the "Obtaining Documentation" section on page viii. 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)-you are connecting to • Type of connector, male or female, needed to connect to the device • Signaling standard required by the device About DTE and DCE Devices A device that communicates over a synchronous serial interface is either a DTE or a DCE device. A DCE device provides a clock signal between the device and the router. A DTE device does not provide a clock signal. DTE devices usually connect to DCE devices. The documentation that accompanied the device should tell you whether it is DTE or DCE. (Some devices have a jumper to select DTE or DCE mode.) If you cannot find this information in your documentation, see Table 5-1 to help you determine the proper device type. OL-2485-20 Cisco Network Modules Hardware Installation Guide 5-1