Cisco 3725 Software Configuration Guide - Page 67

Chapter 3 Configuring with the Command-Line Interface Configuring Asynchronous/Synchronous Serial Network Modules or WAN Interface Cards Command Step 12 Router(config-if)# dce-terminal-timing-enable Step 13 Router(config-if)# invert-txc Step 14 Router(config-if)# nrzi-encoding Step 15 Router(config-if)# exit Step 16 Router(config)# Ctrl-z Router# Purpose When a port is operating in DCE mode, the default operation is for the DCE to send serial clock transmit (SCT) and serial clock receive (SCR) clock signals to the DTE, and for the DTE to return a serial clock transmit external (SCTE) signal to the DCE. If the DTE does not return SCTE, enter this command to configure the DCE port to use its own clock signal. Routers that use long cables might experience high error rates when operating at higher transmission speeds, because the clock and data signals can shift out of phase. If a DCE port is reporting a high number of error packets, inverting the clock using this command can often correct the shift. All serial interfaces support both nonreturn to zero (NRZ) and nonreturn to zero inverted (NRZI) formats. NRZ is the default; NRZI is commonly used with EIA/TIA-232 connections in IBM environments. To enable NRZI encoding on an interface, enter this command. Exit back to global configuration mode. Repeat Step 4 through Step 14 if your router has more that one serial interface that you need to configure. When you finish configuring interface, return to enable mode. Table 3-1 Half-Duplex Timer Commands Timer CTS delay1 CTS drop timeout DCD drop delay DCD transmission start delay RTS2 drop delay RTS timeout Transmit delay Syntax half-duplex timer cts-delay half-duplex timer cts-drop-timeout half-duplex timer dcd-drop-delay half-duplex timer dcd-txstart-delay half-duplex timer rts-drop-delay half-duplex timer rts-timeout half-duplex timer transmit-delay Default Setting (Milliseconds) 100 5000 100 100 100 2000 0 OL-1957-04 Software Configuration Guide for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers 3-7