3Com 4200G 12-Port Configuration Manual page 125

Where xxxx is the IP address or the host name of the switch operating as the Telnet
server. You can use the ip host to assign a host name to a switch.
4 Enter the password. If the password is correct, the CLI prompt (such as <S4200G>)
appears. If all VTY user interfaces of the switch are in use, you will fail to establish the
connection and receive the message that says "All user interfaces are used, please try
later!".
5 After successfully Telneting to the switch, you can configure the switch or display the
information about the switch by executing corresponding commands. You can also
type ? at any time for help.
Telnet Connection Establishment 111