3Com CS/2500 manual SLP, and Trivial File Transfer Protocol Tftp, Next section

4-8 CHAPTER 4: CONFIGURATION

Network Boot String	Specifies the filename of the image to be downloaded from an RBCS or
	TFTP/FTP server and executed. This string can be up to 128 characters
	long. The default is “_cs200 “ (without the quotation marks).
	If your boot protocol is System Load Protocol (SLP), do not modify the
	default network boot string.
	If your boot protocol is TFTP and your Address Discovery Protocol is
	Local Information, you must change the default network boot string to
	the complete pathname of the file you want to download. The default,
	“_cs200,” is not a valid filename. The pathname you enter depends on
	your UNIX® platform or generic TFTP server. For example, the boot
	string for a CS/2500 booting multiprotocol software version 6.2 from a
	DOS TFTP server would be “T25V62 “ (without the quotation marks).
Boot Retries	Specifies server behavior if a boot attempt fails. If you set “Try One
	Time,” the server tries to boot only once. If you set “Try Forever,” the
	server continues trying to boot until a suitable boot source is discovered.
Boot Protocol	Determines the file transfer protocol the communications server uses
	when it downloads software from an RBCS or generic TFTP/FTP server.
	The choices are Bridge Transport Protocol (BTP), System Load Protocol
	(SLP), and Trivial File Transfer Protocol (TFTP).
	BTP is a 3Com proprietary load protocol. This protocol was formerly
	used with 3Com Network Control Servers (NCSs). 3Com no longer
	supports NCS software, and you should not select this protocol. SLP is
	3Com’s implementation of the 802.1 standard System Load Protocol.
	TFTP is a file transfer protocol that is part of the TCP/IP protocol suite.
	If you are configuring your server to boot from an RBCS server, you can
	use either SLP or TFTP. If you boot from a TFTP server, use TFTP.
	If you select SLP as your boot protocol, the server uses the file specified
	by Network Boot String as the boot source. You do not need to
	configure additional parameters. If you select TFTP, you need to
	configure several other parameters. These parameters are described in
	the next section.