65• If the check is passed, the receiver sends an acknowledgement message to the sender. Uponreceiving the message, the sender continues to send the next packet.• If the check fails, the receiver sends a negative acknowledgement message to the sender. Uponreceiving the message, the sender retransmits the packet.Modifying Serial Interface ParametersSometimes, we need to increase the baud rate of a serial interface to save software upgrade time, orlower the baud rate to guarantee transmission reliability. This section describes how to adjust the baudrate of a serial interface.Enter 2 in the main BootWare menu to enter the serial interface submenu. Then, enter 5 and the systemprompts for changing a baud rate.============================================================|Note:'*'indicates the current baudrate || Change The HyperTerminal's Baudrate Accordingly ||----------------------------------------------------||<1> 9600(Default)* ||<2> 19200 ||<3> 38400 ||<4> 57600 ||<5> 115200 ||<0> Exit |==========================================================================Enter your choice(0-5):Select a proper baud rate, 5 for 115200 bps for example. The following prompt appears:Baudrate has been changed to 115200 bps.Please change the terminal's baudrate to 115200 bps, press ENTER when ready.Since the baud rate of the serial interface on the router is changed to 115200 bps, whereas the terminalbaud rate remains 9600 bps, they cannot communicate with each other. Change the baud rate on theconsole terminal to the one selected for downloading software.Perform the following configurations on the console terminal:Figure 58 Disconnect terminalSelect File > Properties, and press Configure… to change the baud rate to 115200 bps: