User`s guide

Introduction 1-1
Chapter 1
Introduction
Product Description
The DIGITAL MultiSwitch 300 is a 12-port Fast Ethernet switch featuring eight
autonegotiating 10/100BaseTX ports and up to four additional 10/100BaseTX/FX
uplink ports. The MultiSwitch 300 provides a cost-effective solution for increasing the
available bandwidth and distance of Fast Ethernet installations by dividing the network
into segments and insulating each from the others’ local traffic. Since each port
autonegotiates either a 10 Mb/s or a 100 Mb/s connection, the MultiSwitch 300 allows
you to upgrade your existing 10 Mb/s network devices to 100 Mb/s as needed.
Each switch supports up to 4096 addresses. Up to four additional ports are available
by using 10/100BaseTX/FX plug-in modules (two ports per module are added).
Delays in data transfer are eliminated through the MultiSwitch 300 parallel store-and-
forward architecture with direct port-to-port transfer. Its proprietary hardware enables
the switch to handle wire speed reception, including broadcast and multicast frames,
through a filtering and forwarding rate of 700,000 packets per second. Unique
selective flow control improves performance by preventing lost packets due to buffer
overload. This feature is critical for sliding window network operating systems (NOSs)
such as TCP/IP and Novell NetWare 4.2, and is available on 10/100 Mb/s half-duplex
ports and 100 Mb/s full-duplex ports.
Up to 200 Mb/s point-to-point connections over standard Fast Ethernet cabling can be
achieved with full-duplex adapter cards made for supporting high-end workstations
and applications. Furthermore, full-duplex operation eliminates the Fast Ethernet
distance limitation of 200 to 400 m (depending on the media type), enabling
transmission distances up to 18 km over fiber optic cable.
Broadcast and security domains may be defined, creating virtual networks that allow
secure workgroups and better manage network traffic. Any filter can be defined based
on multicast/broadcast, source port, destination port, and destination address.
Additional VLAN features include the ability to set virtual broadcast domains and
virtual security LANs. Further reliability is provided through complete runt and CRC
filtering.