Amer Networks SS2R48G4i V2 - Manual (Page 69)

SS2R24G4i/SS2R48G4i
58
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entry = 0x10010
size = 0x1077f8
Step 5
Execute “write nos.img” in BootROM mode. The following saves the system update image file.
[Boot] writeimg
Programming...
Program OK.
Step 6
After successful upgrade, execute “run” command in BootROM mode to return to CLI configuration
interface.
5.5.2 FTP/TFTP Upgrade
5.5.2.1 Introduction To FTP/TFTP
FTP(File Transfer Protocol)/TFTP(Trivial File Transfer Protocol) are both file transfer protocols that
belonging to fourth layer(application layer) of the TCP/IP protocol stack, used for transferring files
between hosts, hosts and switches. Both of them transfer files in a client-server model. Their
differences are listed below.
FTP builds upon TCP to provide reliable connection-oriented data stream transfer service. However,
it does not provide file access authorization and uses simple authentication mechanism(transfers
username and password in plain text for authentication). When using FTP to transfer files, two
connections need to be established between the client and the server a management connection and
a data connection. A transfer request should be sent by the FTP client to establish management
connection on port 21 in the server, and negotiate a data connection through the management
connection.
There are two types of data connections active connection and passive connection.
In active connection, the client transmits its address and port number for data transmission to the
sever, the management connection maintains until data transfer is complete. Then, using the address
and port number provided by the client, the server establishes data connection on port 20 (if not
engaged) to transfer data; if port 20 is engaged, the server automatically generates some other port
number to establish data connection.
In passive connection, the client, through management connection, notify the server to establish a
passive connection. The server then creates its own data listening port and informs the client about the
port, and the client establishes data connection to the specified port.
As data connection is established through the specified address and port, there is a third party to
provide data connection service.
TFTP builds upon UDP, providing unreliable data stream transfer service with no user