Installation Manual
H3C SecPath F1000-E Firewall
Chapter 6 Maintaining Software
6-11
6.3 Upgrading BootWare and an Application Through a Serial
Interface
6.3.1 Introduction to Xmodem
Use Xmodem when upgrading BootWare and an application through a serial interface.
Xmodem is a file transfer protocol that is widely used due to its simplicity and high
performance. Xmodem transfers files through a serial interface. It supports two types of
data packets (128 bytes and 1 KB), two check methods (checksum and CRC), and
error packet retransmission mechanism (generally the maximum number of
retransmission attempts is 10).
The Xmodem transmission procedure is completed by the cooperation of a receiving
program and a sending program. The receiving program sends a negotiation character
to negotiate a packet check method. After the negotiation, the sending program starts
to transmit data packets. When receiving a complete packet, the receiving program
checks the packet using the agreed method.
z
If the check succeeds, the receiving program sends an acknowledgement
character and the sending program proceeds to send another packet.
z
If the check fails, the receiving program sends a negative acknowledgement
character and the sending program retransmits the packet.
6.3.2 Modifying Serial Interface Parameters
In actual applications, you need to make the serial interface baud rate higher to save
upgrading time or make it lower to guarantee transmission reliability. This section
introduces how to adjust the serial interface baud rate.
Enter the BootWare main menu and select
2
to enter the serial interface submenu, and
then select
5
on the submenu to modify the baud rate. The system displays the
following:
========================<BAUDRATE SET>=======================
|Note:'*'indicates the current baudrate |
| Change The HyperTerminal's Baudrate Accordingly |
| Press 'Enter' to exit with things untouched. |
|--------------------<Baudrate Available>-------------------|
| <1> 9600(Default) * |
| <2> 19200 |
| <3> 38400 |
| <4> 57600 |
| <5> 115200 |
| <0> Exit |
=============================================================
