IBM EtherLink XL manual Frequently Asked Questions B-19

Frequently Asked Questions B-19

Table B-2Frequently Asked Questions (continued)

QuestionAnswer

What is a Magic Packet?

A Magic Packet is a valid Ethernet packet that contains a synchronization stream immediately followed by 16 repetitions of the destination MAC address. This Magic Packet is not protocol-specific as long as the protocol contains the sync stream and the 16 repetitions. This Magic Packet can be routed in order to wake up a remote PC. Since it is a valid Ethernet address, the Remote Wake-Up adapter can accept broadcast or multicast packets.

What is a cable	The adapter can also be awakened by
connect/disconnect?	connecting or disconnecting the network cable.
What is Fast IP?	Fast IP is software that improves performance on
	switched networks. Fast IP allows end systems
	(desktops and servers) to discover switched
	communication paths. By creating switched
	shortcuts, Fast IP allows end stations to bypass
	the router and transfer data across wire-speed
	switched paths. Fast IP is part of 3Com’s
	DynamicAccess software, an advanced network
	driver that brings intelligence to end systems to
	provide improved network performance and
	control.
What are the PC and network	Client requirements:
requirements to run Fast IP?	PC running Windows 95 or Windows NT
	(versions 4 or 3.51), 3Com 3C905B-TX adapter,
	and the TCP/IP stack
	Network requirements:
	Switched path between stations and single
	broadcast domain
What are the network	Fast IP is designed to bypass the router,
configuration requirements for	particularly where the router is a bottleneck, as
Fast IP?	well as to leverage the switched infrastructure.
	For Fast IP to create shortcuts around routers,
	there must be a switched path between source
	and destination.

What is the performance gain when using Fast IP?

Fast IP bypasses the router to provide increased performance in switched networks even if only a small number of network nodes use Fast IP.

The performance gain obtained when deploying Fast IP is directly related to traffic load on the backbone router. The more traffic pumped to the router, the greater the latency and response time and the higher the performance gain. Internal tests show performance increases on the order of 600% when routers are loaded at 70 to 75%.