3Com XL PCI User Manual page 48

4-18 C
HAPTER
Table 4-2 Frequently Asked Questions (continued)
Question
What is a Magic Packet?
What is a cable
connect/disconnect?
What is Fast IP?
What are the PC and network
requirements to run Fast IP?
What are the network
configuration requirements for
Fast IP?
What is the performance gain
when using Fast IP?
4: T
ROUBLESHOOTING
Answer
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
NIC can accept broadcast or multicast packets.
The NIC can also be awakened by connecting or
disconnecting the network cable.
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.
Client requirements:
PC running Windows 95 or Windows NT
(versions 4 or 3.51), 3Com 3C905B-TX NIC,
and the TCP/IP stack
Network requirements:
Switched path between stations and single
broadcast domain
Fast IP is designed to bypass the router,
particularly where the router is a bottleneck, as
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.
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%.