Allied Telesis AT-FS724L User manual

AT-FS724L
Fast Ethernet Switch
Installation Guide
PN 613-50464-00 Rev A

Copyright ©2003 Allied Telesyn, Inc.
960 Stewart Drive, Suite B, Sunnyvale, CA 94085, USA
All rights reserved. No part of this publication may be reproduced without prior written permission
from Allied Telesyn, Inc.
Ethernet is a registered trademark of Xerox Corporation. All other product names, company names,
logos or other designations mentioned herein are trademarks or registered trademarks of their
respective owners.
Allied Telesyn, Inc. reserves the right to make changes in specifications and other information
contained in this document without prior written notice. The information provided herein is subject
to change without notice. In no event shall Allied Telesyn, Inc. be liable for any incidental, special,
indirect, or consequential damages whatsoever, including but not limited to lost profits, arising out of
or related to this manual or the information contained herein, even if Allied Telesyn, Inc. has been
advised of, known, or should have known, the possibility of such damages.

iii
Electrical Safety and Emission Compliance
Statement
Standards: This product meets the following standards.
U.S. Federal Communications Commission
Declaration Of Conformity
Manufacturer Name: Allied Telesyn, Inc.
Manufacturer Address: 960 Stewart Drive, Suite B
Sunnyvale, CA 94085, USA
Manufacturer Telephone: [phone]
Declares that the product: Fast Ethernet Switch
Model Number: AT-FS724L
This product complies with FCC Part 15B, Class B Limits:
This device complies with part 15 of the FCC Rules. Operation is subject
to the following two conditions: (1) This device must not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
Radiated Energy
Note: This equipment has been tested and found to comply with the limits
for a Class B digital device pursuant to Part 15 of FCC Rules. These
limits are designed to provide reasonable protection against harmful
interference in a residential installation. This equipment generates, uses
and can radiate radio frequency energy and, if not installed and used in
accordance with instructions, may cause harmful interference to radio or
television reception, which can be determined by turning the equipment
off and on. The user is encouraged to try to correct the interference by one
or more of the following measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and the receiver.
- Connect the equipment into an outlet on a circuit different from that to
which the receiver is connected.
- Consult the dealer or an experienced radio/TV technician for help.
Changes and modifications not expressly approved by the manufacturer
or registrant of this equipment can void your authority to operate this
equipment under Federal Communications Commission rules.
Industry Canada
This Class B digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.
Cet appareil numérique de la classe B respecte toutes les exigences du
Règlement sur le matériel brouilleur du Canada.

Electrical Safety and Emission Compliance Statement
iv
RFI Emission FCC Class B, EN55022 Class B,
VCCI Class B, C-TICK 1
Warning: In a domestic environment this product may cause radio
interference in which case the user may be required to take adequate
measures. 2
Immunity EN55024 3
Electrical Safety EN60950 (TUV), UL60950 (cULus)4
Important: Appendix B contains translated safety statements for installing
this equipment. When you see the , go to Appendix B for the translated
safety statement in your language.
Wichtig: Anhang B enthält übersetzte Sicherheitshinweise für die
Installation dieses Geräts. Wenn Sie sehen, schlagen Sie in Anhang B
den übersetzten Sicherheitshinweis in Ihrer Sprache nach.
Vigtigt: Tillæg B indeholder oversatte sikkerhedsadvarsler, der vedrører
installation af dette udstyr. Når De ser symbolet , skal De slå op i tillæg
B og finde de oversatte sikkerhedsadvarsler i Deres eget sprog.
Belangrijk: Appendix B bevat vertaalde veiligheidsopmerkingen voor het
installeren van deze apparatuur. Wanneer u de ziet, raadpleeg
Appendix B voor vertaalde veiligheidsinstructies in uw taal.
Important: L'annexe B contient les instructions de sécurité relatives à
l'installation de cet équipement. Lorsque vous voyez le symbole ,
reportez-vous à l'annexe B pour consulter la traduction de ces instructions
dans votre langue.
Tärkeää: Liite B sisältää tämän laitteen asentamiseen liittyvät käännetyt
turvaohjeet. Kun näet -symbolin, katso käännettyä turvaohjetta
liitteestä B.
Importante: l’Appendice B contiene avvisi di sicurezza tradotti per
l’installazione di questa apparecchiatura. Il simbolo , indica di consultare
l’Appendice B per l’avviso di sicurezza nella propria lingua.
Viktig: Tillegg B inneholder oversatt sikkerhetsinformasjon for installering
av dette utstyret. Når du ser , åpner du til Tillegg B for å finne den
oversatte sikkerhetsinformasjonen på ønsket språk.
Importante: O Anexo B contém advertências de segurança traduzidas para
instalar este equipamento. Quando vir o símbolo , leia a advertência de
segurança traduzida no seu idioma no Anexo B.
Importante: El Apéndice B contiene mensajes de seguridad traducidos
para la instalación de este equipo. Cuando vea el símbolo , vaya al
Apéndice B para ver el mensaje de seguridad traducido a su idioma.
Obs! Bilaga B innehåller översatta säkerhetsmeddelanden avseende
installationen av denna utrustning. När du ser , skall du gå till Bilaga B
för att läsa det översatta säkerhetsmeddelandet på ditt språk.

v
Table of Contents
Electrical Safety and Emission Compliance Statement ......................iii
Table of Contents ........................................................................................... v
Welcome to Allied Telesyn .........................................................................vii
Where to Find Related Guides.........................................................................vii
Document Conventions ....................................................................................vii
Contacting Allied Telesyn ...............................................................................viii
Online Support .........................................................................................viii
E-mail and Telephone Support................................................................viii
Returning Products ..................................................................................viii
For Sales or Corporate Information ........................................................viii
Chapter 1
Overview .......................................................................................................... 1
Key Features....................................................................................................... 2
Status LEDs........................................................................................................ 3
Twisted Pair Ports.............................................................................................. 3
Port Speed.................................................................................................... 3
Duplex Mode................................................................................................ 4
Auto MDI/MDI-X......................................................................................... 4
MAC Address Table............................................................................................ 5
Store and Forward.............................................................................................. 6
Backpressure and Flow Control ........................................................................ 6
Internal Power Supply ....................................................................................... 7
Network Topologies ............................................................................................ 8
Power Workgroup Topology........................................................................ 8
Cascade Topology ........................................................................................ 9
Chapter 2
Installation .................................................................................................... 11
Verifying the Package Contents ...................................................................... 11
Planning the Installation................................................................................. 12
Selecting a Site .......................................................................................... 12
Reviewing Safety Guidelines .................................................................... 13
Installing the Switch on a Table or Desktop................................................... 14
Rackmounting the Switch................................................................................ 15
Warranty Registration ..................................................................................... 17

Table of Contents
vi
Chapter 3
Troubleshooting ...........................................................................................19
Appendix A
Technical Specifications ............................................................................21
Physical .............................................................................................................21
Environmental ..................................................................................................21
Electrical Rating ...............................................................................................22
Agency Compliance...........................................................................................22
Pinout Assignments..........................................................................................23
Appendix A
Translated Safety and Emission Information .......................................25

vii
This guide contains instructions on how to install the AT-FS724L Fast
Ethernet Switch.
Where to Find Related Guides
The Allied Telesyn web site at www.alliedtelesyn.com offers you an easy
way to access the most recent documentation, software, and technical
information for all of our products. For product guides, select “Support &
Services” from our web site.
Document Conventions
This guide uses the following conventions:
Note
Notes provide additional information.
Caution
Cautions informs you that performing or omitting a specific action may
result in equipment damage or loss of data.
Warning
Warnings informs you that performing or omitting a specific action may
result in bodily injury.
Welcome to Allied Telesyn

Welcome to Allied Telesyn
viii
Contacting Allied Telesyn
This section provides Allied Telesyn contact information for technical support
as well as sales or corporate information.
Online Support
You can request technical support online by accessing the Allied Telesyn
Knowledge Base from the following web site: http://kb.alliedtelesyn.com.
You can use the Knowledge Base to submit questions to our technical support
staff and review answers to previously asked questions.
E-mail and Telephone Support
For Technical Support via E-mail or telephone, refer to the Support & Services
section of the Allied Telesyn web site: http://www.alliedtelesyn.com.
Returning Products
Products for return or repair must first be assigned a Return Materials
Authorization (RMA) number. A product sent to Allied Telesyn without a
RMA number will be returned to the sender at the sender’s expense.
To obtain a RMA number, contact Allied Telesyn’s Technical Support at our
web site: http://www.alliedtelesyn.com.
For Sales or Corporate Information
You can contact Allied Telesyn for sales or corporate information at our web
site: http://www.alliedtelesyn.com. To find the contact information for your
country, select “Contact Us” then “Worldwide Contacts.”

1
Chapter 1
Overview
The AT-FS724L is Fast Ethernet switch that provides simple, cost-effective
solutions for switching between 10 Mbps and 100 Mbps.
The AT-FS724L switch features 24 10/100Base-TX twisted pair ports. Each
twisted pair port has a RJ-45 connector and a maximum operating distance of
100 meters (328 feet). These ports are capable of Auto-Negotiating at 10 or 100
Mbps and feature half- and full-duplex operation.
The AT-FS724L features an internal power supply and are designed for
desktop or rackmount installation.
These switches are easy to install and do not require software configuration or
management.
Figure 1 illustrates the front panel of the AT-FS724L switch.
Figure 1 AT-FS724L Front Panel
Table 1 lists the number of ports, connector type, and maximum operating
distance for each switch.
Table 1 AT-FS724L Switch
Model Number of
Ports
10/100Base-TX
Connector Maximum Operating Distance
AT-FS724L 24 RJ-45 100 m (328 ft)
AT-FS724L
24 Port Fast Ethernet Switch
18 20 22 24
10 12 14 162468
91113151357 17 19 21 23
100M
LNK/ACT
100M
LNK/ACT
POWER
1 3 5 7 9 11 13 15 17 19 21 23
2 4 6 8 10 12 14 16 18 20 22 24
AUTO
MDI/ MDI-X

Overview
2
Key Features
The AT-FS724L switch has the following key features:
24 10/100Base-TX ports
System and port LEDs
Auto MDI/MDI-X on all ports
Auto-Negotiation on all ports (IEEE 802.3u-compliant)
Store and forward switching mode
Backpressure and flow control (IEEE 802.3x-compliant)
Store and forward packet handling
Storage for up to 4,000 MAC addresses
MAC address aging time at 300 seconds
Embedded 256KB packet buffer or more
Broadcast storm protection
For use on a desktop or rackmount

AT-FS724L Fast Ethernet Switch Installation Guide
3
Status LEDs
Table 2 lists the status LEDs for the AT-FS724L switch.
Table 2 Status LEDs
Twisted Pair Ports
The AT-FS724L switch has 24 10Base-T/100Base-TX twisted pair ports. Each
twisted pair port features a RJ-45 connector. The maximum operating distance
for the twisted pair ports is 100 meters (328 feet) when operating at either
10 Mbps or 100 Mbps.
Port Speed
The twisted pair ports are compliant with the 10Base-T and 100Base-TX
standards and are capable of either 10 Mbps or 100 Mbps operation. Since the
ports are IEEE 802.3u Auto-Negotiation compliant, the switch will set the
port speed automatically. With Auto-Negotiation, the speed of the ports are
set automatically by the switch after it determines the speed of the end-node
connected to the port. Auto-Negotiation is designed to ensure that the port on
the switch and the end-node are operating at the same speed and that they
are communicating at the highest possible common speed between the
devices. For example, if an end-node is capable of only 10 Mbps, the switch
then sets the port connected to the end-node to 10 Mbps.
LED Color Description
POWER Green
OFF
Power is applied to the switch.
No power is applied to the switch.
LNK/ACT Green
Blinking
OFF
A valid link has been established on the port.
The port is transmitting data.
A link has not been detected on the port.
100M Green
OFF
The port is operating at 100 Mbps.
The port is operating at 10 Mbps.

Overview
4
Duplex Mode
Duplex mode refers to the way an end-node sends and receives data on the
network. An end-node can operated in either half- or full-duplex mode
depending on its capabilities. An end-node that is operating in half-duplex
mode can either send data or receive data, but it cannot do both at the same
time. An end-node that is operating in full-duplex mode can send and receive
data simultaneously. The best network performance is achieved when an end-
node can operate at full-duplex, since the end-node is able to send and receive
data simultaneously.
The twisted pair ports on the AT-FS724L switch can operate in either half-
duplex or full-duplex mode and can deliver up to 200 Mbps of bandwidth to the
end-nodes. Since these twisted pair ports are IEEE 802.3u-compliant, the
duplex mode can be set automatically through Auto-Negotiation. With Auto-
Negotiation, if the end-node is capable of full-duplex, the port is set
automatically to full-duplex mode. If the end-node is capable of half-duplex,
the port is set automatically to half-duplex mode.
Note
In order for the twisted pair port on the AT-FS724L switch to
successfully Auto-Negotiate its duplex mode with an end-node, the end-
node should also be using Auto-Negotiation. Otherwise, a duplex mode
mismatch can occur. The twisted pair port, using Auto-Negotiation, will
default to half-duplex if it detects that the end-node is not using Auto-
Negotiation. This will result in a mismatch if the end-node is operating
at a fixed duplex mode of full-duplex.
Auto MDI/MDI-X
A twisted pair port on a 10 Mbps or 100 Mbps Ethernet network device can
have one of two possible wiring configurations: MDI or MDI-X. A twisted pair
port on a PC, router, or bridge is typically wired as MDI, while a twisted pair
port on a switch or hubs is usually MDI-X.
To connect two 10 Mbps or 100 Mbps network devices together that have
dissimilar port wiring configurations, such as an MDI to MDI-X, you would
use a straight-through twisted pair cable. To connect two networks devices
that have the same wiring configuration, such as MDI to MDI, you would use
a crossover cable.
The AT-FS724L switch features automatic MDI/MDI-X. The twisted pair port
automatically determines the configurations of the port on the device to which
it is connected and then configures itself appropriately. For example, if a port
on a switch is connected to a port on a bridge, which is typically wired as MDI,

AT-FS724L Fast Ethernet Switch Installation Guide
5
the port on the switch automatically configures itself as MDI-X. This feature
allows you to use either a crossover cable or a straight-through cable when
connecting a device to a twisted pair port.
MAC Address Table
The heart of an Ethernet switch is the Media Access Control (MAC) address
table. Every device that you attach to an Ethernet network has a MAC address.
This address is assigned to the device by the device’s manufacturer. For
example, each Network Interface Card (NIC) that you install into your network
computers has a MAC address that was assigned to it by the card’s
manufacturer.
A switch’s MAC address table is a list of the MAC addresses of the devices that
are connected to its ports. The switch uses this table to direct data frames to
their appropriate destination end-nodes, and in some cases, to discard frames
that it receives. The switch creates the MAC address table by examining the
frames that it receives on its ports. Each frame is examined for its source
address; that is, the MAC address of the end-node that sent the frame. The
switch checks to determine whether the address is already in its MAC address
table. If it is not, the switch adds the address to the table along with the port
number on which the frame was received. The result is a table that contains a
list of all the MAC addresses of end-nodes that have sent frames to the switch
and the ports on the switch to which the end-nodes are connected.
The switch also checks the destination MAC address of each frame it receives.
The destination address is the MAC address of the end-node to which the frame
is intended. If the address is in the table, the switch directs the frame directly
to the port where the end-node is located. This helps to ensure that end-nodes
will only receive traffic that is intended for them and not have to deal with
traffic intended for other end-nodes.
If the destination address is not in the MAC address table, the switch
broadcasts the frame to all switch ports. When the destination end-node
responds, the switch will be able to match the address to a port so that the next
time a frame is destined to that particular end-node, the switch will be able to
forward the frame to the correct port instead of having to broadcast the frame
to all ports.
In some cases a switch will even discard a frame. If the switch receives a frame
that is destined to an end-node on the same port on which the frame was
received, the switch discards the frame.
The MAC address table in the AT-FS724L switch can store up to 4,000 MAC
addresses. To prevent the table from becoming filled with addresses of end-
nodes that are no longer active, the switch has a MAC address aging timer.

Overview
6
This timer will delete a MAC address from the table if it does not see a frame
from the end-node with the address on any port after five minutes (300
seconds). The aging timer also helps to ensure that the table is correct should
an end-node be moved from one port on the switch to another port.
Store and Forward
These Fast Ethernet Switches use store and forward as the method for
receiving and transmitting frames. When an Ethernet frame is received on a
switch port, the switch does not retransmit the frame out the destination port
until it has received the entire frame and stored the frame in a port buffer. It
then examines the frame to determine if it is a valid frame. Invalid frames,
such as fragments or runts, are discarded by the switch. This insures that only
valid frames are transmitted out the switch ports and that damaged frames are
not propagated on your network.
Backpressure and Flow Control
In order to maintain the orderly movement of data between the end-nodes, an
Ethernet switch may periodically need to signal an end-node to stop sending
data. This can occur under several circumstances. For example, if two end-
nodes are operating at different speeds, the switch, while transferring data
between the end-nodes, might need to instruct the faster end-node to stop
transmitting data to allow the slower end-node to catch up. An example of this
would be when a server operating at 100 Mbps is sending data to a workstation
operating at only 10 Mbps.
How a switch signals an end-node to stop transmitting data differs depending
on the speed and duplex mode of the end-node and switch port. A twisted pair
port operating at 100 Mbps port and half-duplex mode stops an end-node from
transmitting data by forcing a collision. A collision on an Ethernet network
occurs when two end-nodes attempt to transmit data using the same data link
at the same time. A collision causes end-nodes to stop sending data. When the
switch needs to stop a 100 Mbps, half-duplex end-node from transmitting data,
it forces a collision on the data link, which stops the end-node. Once the switch
is ready to receive data again, the switch stops forcing collisions. This is
referred to as backpressure.
A port operating at 100 Mbps and full-duplex mode uses PAUSE frames, as
specified in the IEEE 802.3x standard, to stop the transmission of data from an
end-node. Whenever the switch wants an end-node to stop transmitting data,
it issues this frame. The frame instructs the end-node to cease transmission.
The switch continues to issue PAUSE frames until it is ready again to receive
data from the end-node. This is referred to as flow control.

AT-FS724L Fast Ethernet Switch Installation Guide
7
Internal Power Supply
The AT-FS724L uses a universal internal switching power supply operating at
100-120/200-240V AC. The frequencies are 50/60 Hz, 0.5A at all input voltage
+/-3%. Allied Telesyn ships power cords with these units to the U.S.,
Continental Europe, and the U.K. The switches require input of 100-120 or
200-240V AC. The AT-FS724L switch has a maximum power consumption of
15W.

Overview
8
Network Topologies
The AT-FS724L switch can be used in a variety of network topologies, such as
a power workgroup or cascade. Both topologies are described below.
Power Workgroup Topology
A power workgroup topology, shown in Figure 2, allows each end-node to
directly connect to a 10/100Base-TX port on an AT-FS724L switch. This gives
each end-node a dedicated 10 Mbps or 100 Mbps link.
Figure 2 Power Workgroup Topology
AT-FS724L
24 Port Fast Ethernet Switch
18 20 22 24
10 12 14 162468
91113151357 17 19 21 23
100M
LNK/ACT
100M
LNK/ACT
POWER
1 3 5 7 9 11131517192123
2 4 6 8 10 12 14 16 18 20 22 24
AUTO
MDI/ MDI-X
Workstations
Workstations Server
10 Mbps
100 Mbps

AT-FS724L Fast Ethernet Switch Installation Guide
9
Cascade Topology
Connecting two similar networking devices together is called ‘cascading’.
Figure 3 illustrates this topology where Port 24 on the AT-FS724L switch is
connected to Port 8 on the AT-FS716 switch. Since Port 24 is wired as auto
MDI/MDI-X, a crossover or straight-through Category 5 or better twisted pair
cable can be used.
Figure 3 Cascade Topology
AT-FS724L
24 Port Fast Ethernet Switch
18 20 22 24
10 12 14 162468
91113151357 17 19 21 23
100M
LNK/ACT
100M
LNK/ACT
POWER
1 3 5 7 9 11131517192123
2 4 6 8 10 12 14 16 18 20 22 24
AUTO
MDI/ MDI-X
Workstations
AT-FS724L
Workstations Server
AT-FS716
100 m (328 ft)
10 Mbps
100 Mbps

11
Chapter 2
Installation
Verifying the Package Contents
Make sure the following items are included in your package. If any item is
missing or damaged, contact your Allied Telesyn sales representative for
assistance.
❑One AT-FS724L Fast Ethernet Switch
❑Four protective feet (for desktop use only)
❑This installation guide
❑Warranty card
❑An AC power cord
❑Rackmounting kit

Installation
12
Planning the Installation
Be sure to observe the following guidelines when planning the installation of
your switch.
❑The end-nodes connected to the twisted pair port can operated at
either 10 Mbps or 100 Mbps and half- or full-duplex mode.
❑The end-node connected to a port on the switch can be a network
adapter card, repeater, router, hub, or another switch.
❑Refer to Table 3 for the cabling specifications for the twisted pair
ports.
Table 3 10/100Base-TX Twisted Pair Port Cabling Specifications
Selecting a Site
Be sure to observe the following guidelines when selecting a site for your
switch.
❑Select a site that is dust-free and moisture-free.
❑Select a site that will allow you to easily access the switch’s power and
data cables.
❑The twisted pair port cabling must be kept away from sources of
electrical noise, such as radios, transmitters, power lines, broadband
amplifiers electrical motors, and fluorescent fixtures.
❑Make sure the air flow around the switch and through its vents on the
side and back are not restricted.
❑Use dedicated power circuits or power conditioners to supply reliable
power to the switch.
Operating Mode Twisted Pair Cable Maximum Operating
Distance
10Base-T Shielded or unshielded Category 3 or better 100 m (328 ft)
100Base-TX Shielded or unshielded Category 5 or better 100 m (328 ft)