Accton Technology SwitcHub-2s User manual

SwitcHub-2s
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Installation Manual
SwitcHub-2s
2-Port Ethernet Switching Hub
for 10BASE-T/100BASE-TX

Copyright (c) 1996 by Accton Technology Corporation. All rights reserved.
No part of this document may be copied or reproduced in any form or by any means without the
prior written consent of Accton Technology Corporation.
Accton makes no warranties with respect to this documentation and disclaims any implied
warranties of merchantability, quality, or fitness for any particular purpose. The information in this
document is subject to change without notice. Accton reserves the right to make revisions to this
publication without obligation to notify any person or entity of any such changes.
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No. 1 Creation Road III,
Science-based Industrial Park
Hsinchu 300, Taiwan, R.O.C.
Phone: [phone]
FAX: [phone]
BBS: 886-35-770-654
Internet: [email protected]
86$+HDGTXDUWHUV
1962 Zanker Road
San Jose, CA 95112
Phone: [phone]
FAX: [phone]
BBS: 408-452-8828
FAST FAX: [phone]
Accton and SwitcHub are trademarks or registered trademarks of Accton Technology Corporation.
Other trademarks or brand names mentioned herein are trademarks or registered trademarks of
their respective companies.
EH3001
E0496-R03
150652-101

About this Guide i
About this Guide
This guide is designed for the experienced network installer. It describes how
to install and operate Accton’s Fast SwitcHub-2s Ethernet switch. After reading
this manual, you should be able to use the front display panel and configure
options to manage all your network connections.
This manual covers the following topics:
ì Product description, summary of important features and specifications
ì Brief description of the SwitcHub-2s
ì Description of significant components of the unit including LED indicators,
ports and buttons
ì System setup and configuration

Package Contents iii
Package Contents
Carefully unpack the contents of the package and verify them against the checklist
given below.
Package Checklist
æSwitcHub-2s (Model No. EH3001-TX)
æAC power cord
æInstallation manual
æOwner registration card
Please inform your dealer immediately should there be any wrong, missing, or
damaged parts.
If possible, retain the carton, including the original packing materials. Use
them again to repack the unit in case there is a need to return it for repair.
To qualify for product updates and product warranty registration, fill in the
Owner Registration Card and return it to Accton Technology Corporation.

Quick Installation v
Quick Installation
The SwitcHub-2s contains 2 Ethernet ports, each of which supports 100BASE-TX
or 10BASE-T connections, operating at full or half-duplex. The smart design
built into the front display panel and configure options, provides a friendly
interface that simplifies installation and network troubleshooting. If you are
already familiar with basic network operations, you should be able to install this
switch as described below:
1. Unpack the SwitcHub-2s.
2. Find a location close to the network devices you need to connect, and within
easy reach of an electrical outlet.
3. Connect workstations or servers to the MDI-X station ports.
4. Connect to other hubs via the MDI port.
5. Set the transmission mode for each port to full or half-duplex.
6. Verify network communications by ensuring that -
• you have made all the necessary connections
• you can access any connected resources
• the hub’s indicator LEDs are functioning properly
Note: For devices connected directly to either port on the switch, it will
automatically detect transmission speed (10/100 Mbps). However, unless
the connected devices are operating at half-duplex (i.e., system default), you
will have to manually set the transmission mode via the configure button.
(Refer to Full/Half Duplex Mode Selection in Chapter 2).
If you encounter any problems in installing the SwitcHub-2s, refer to Chapter 3 for
a detailed description of installation procedures, or to Appendix A for help in
troubleshooting.

Contents
vii
Chapter 1: Introduction...........................................................1-1
Switching Technology...............................................................................................1-1
Accton’s Smart Extender (The Fast SwitcHub-2s)....................................................1-2
Features of the Fast SwitcHub-2s..............................................................................1-4
Chapter 2: Hardware Description ..........................................2-1
Front Panel ...............................................................................................................2-1
Configure Button..................................................................................................2-2
SmartWatch LED Panel........................................................................................2-3
Power..............................................................................................................2-3
Statistical Display for System Performance....................................................2-4
Setting the Communication Mode ..................................................................2-6
Diagnostics Display Mode..............................................................................2-7
Port Status Display..........................................................................................2-8
Rear Panel ...............................................................................................................2-10
Ethernet Ports.......................................................................................................2-10
Power Socket........................................................................................................2-10
Chapter 3: Setup and Configuration......................................3-1
Pre-Installation Requirements ...................................................................................3-1
Connecting the Hub System......................................................................................3-2
Server/Workstation Connection............................................................................3-2
Daisy-Chain Connection.......................................................................................3-3
Providing Power to the SwitcHub.............................................................................3-4
Diagnostic Tests........................................................................................................3-4

SwitcHub-2s User’s Guide
viii Contents
Setting the Display Mode..........................................................................................3-5
Selections Available.............................................................................................3-6
Bandwidth Utilization.....................................................................................3-6
Packet Forwarding Ratio.................................................................................3-6
Packet Filtering Ratio .....................................................................................3-6
Collision Ratio................................................................................................3-6
Full/Half Duplex Mode Selection...................................................................3-7
Diagnostic Function........................................................................................3-7
Verifying Port Status.................................................................................................3-8
Verifying System Operation......................................................................................3-8
Appendix A: Troubleshooting................................................A-1
Diagnosing Hub Indicators........................................................................................A-1
System Diagnostics ...................................................................................................A-2
Installation............................................................................................................A-2
Configuration........................................................................................................A-2
Hub Integrity ........................................................................................................A-3
Appendix B: Port and Cable Assignments.............................B-1
RJ-45 Port ...............................................................................................................B-1
Appendix C: Specifications....................................................C-1
Product Specifications...............................................................................................C-1
Appendix D: Regulatory Standards Compliance..................D-1
EMI Warning ............................................................................................................D-1
FCC Class B Certification....................................................................................D-1
Voluntary Control Council for Interference (VCCI-2).........................................D-3
EN55022 Declaration of Conformance ................................................................D-3
Safety Compliance.....................................................................................................D-4
Underwriters Laboratories Compliance Statement...............................................D-4
Sicherheitshinweise..............................................................................................D-5

SwitcHub-2s User’s Guide
Contents ix
Appendix E: Product Support Services ................................E-1
Product Registration..................................................................................................E-1
Problem Report .........................................................................................................E-1
Hardware Repair Service...........................................................................................E-1
Software Update and Upgrade Service......................................................................E-2
Bulletin Board Service (BBS) ...................................................................................E-2
Interactive Fast Fax (U.S.A. office) ..........................................................................E-2
Technical Support .....................................................................................................E-3
Limited Warranty......................................................................................................E-4
Customer Remedies..............................................................................................E-4
Return Process......................................................................................................E-5
Accton Distributors ...................................................................................................E-6
Ordering Information ................................................................................................E-6
Glossary
Index
List of Figures
Figure 2.1 The SwitcHub-2s Front Panel................................................................2-1
Figure 2.2 SmartWatch LED Panel.........................................................................2-3
Figure 2.3 The SwitcHub-2s Rear Panel .................................................................2-10
Figure B-1 RJ-45 Connector (on the Hub Side).......................................................B-1
List of Tables
Table B-1 RJ-45 Pin Assignments............................................................................B-1

1-1
Chapter 1: Introduction
Switching Technology
The Ethernet Switch allows simultaneous transmission of multiple packets via
an internal high-speed data channel. This means that it can partition a network
more efficiently than bridges or routers in most environments. The Ethernet
Switch is therefore fast being recognized as one of the most important building
blocks for today’s networking technology.
The learning function in the switching hub stores the address and
corresponding port number of each incoming and outgoing packet in a routing
table. This information is subsequently used to filter packets whose destination
address is on the same segment as the source address. This confines network
traffic to its respective domain, reducing the overall load on the network.
The switch scans the destination address from the packet header, searches the
routing table provided for the incoming port and forwards the packet only if
required, often before fully received. This fast forwarding makes the switch
attractive for connecting servers directly to the network, thereby increasing
throughput and availability. However, the switch is most commonly used to
segment existing hubs, which nearly always improves overall performance. A
switching hub can be easily configured in any Ethernet network to significantly
boost bandwidth using conventional cabling and adapters.

SwitcHub-2s User’s Guide
1-2 Introduction
Accton’s Smart Extender (The Fast SwitcHub-2s)
Accton’s Smart Extender can boost network bandwidth fourfold, depending on
your configuration (i.e., if running at 100Mbps and full-duplex operation for
both ports). It provides two 10/100 Mbps RJ-45 ports (set at full or half-duplex)
to connect to either a subnetwork, or directly to a server or key workstation. In
addition to partitioning an overloaded network, it provides connection between
legacy 10BASE-T networks and the newer generation 100BASE-TX, and can
be configured to operate in either full-duplex or half-duplex data transfer mode
to support the interconnection requirements of other high-speed devices.
This switching hub performs "on-the-fly" cut-through switching, which sends a
packet to the other port according to the destination address scanned from the
packet header. This technique reduces the latency of packet transmission to 20
microseconds or less. Compared to approximately 800 microseconds for a
bridge or 1800 microseconds for a router, both of which have to store the entire
packet before the it can be forwarded, the SwitcHub can deliver a quantum
improvement in your network’s performance.
As a device functioning on the media access control (MAC) layer, the
SwitcHub is protocol independent, and therefore compatible with IEEE802.3,
IEEE802.3u, TCP/IP, NetWare, DECnet and XNS protocols. Accton’s Smart
Extender can be configured as a 2-port bridge for a 10BASE-T environment; it
can provide a connection between conventional 10BASE-T and high-speed
100BASE-TX networks; or can serve as a 2-port bridge in a 100BASE-TX
environment. Moreover, where traditional 100BASE-TX networks restrict the
maximum distance between end-nodes to 205 meters, the Smart Extender
breaks down this barrier. By breaking your network into smaller and more
manageable segments, each linked to the larger network with a switch, the
maximum distance for communications between end-nodes is unlimited.

SwitcHub-2s User’s Guide
Introduction 1-3
Traditional bridges and routers use a switching method called store-and-
forward in which the entire frame must be received before the bridge can
perform a table look-up for the destination node and forward the packet to the
corresponding port. As a result, each packet is delayed by approximately 800
microseconds. It may be necessary to use store-and-forward when a lot data
errors are occurring over the network, or when connecting to very slow devices.
Compared to this “safe” mode of operation, cut-through reduces the packet
transmission delay to around 20 microseconds by picking the destination
address out of the header as soon as its received, and directing the frame to the
appropriate port long before the full packet has been received. The remaining
technique, employed to improve data reliability, is called fragment-free cut-
through. It uses a more conservative approach to cut-through that waits until
the collision window has elapsed (i.e., the first full 64 bytes has been received)
before processing the packet. This prevents runts from being passed along,
effectively cleaning up the data stream.
Although cut-though switching is recommended as the fastest method for most
applications, the other methods mentioned above are also supported by the
SwitcHub-2s to guarantee flawless performance. To ensure that you can
manage any kind of network load, the Smart Extender uses adaptive cut-
through switching based on Accton’s smart algorithm. This method
dynamically changes the way it handles data passing through the switch based
on the current error rate. These switching alternatives start at standard cut-
through for a clean data environment, change to fragment-free cut-through for a
moderate error rate, and then progress to store-and-forward for a highly
contentious environment. By using this method, the SwitcHub-2s delivers the
best networking performance under any environment.

SwitcHub-2s User’s Guide
1-4 Introduction
Features of the Fast SwitcHub-2s
• Conforms to the IEEE 802.3 and IEEE 802.3u specifications, as well as
10BASE-T and 100BASE-TX standards
• Provides two independent RJ-45 10BASE-T / 100BASE-TX Ethernet station
ports, where each logical port consists of 1 MDI port (for connection to hubs
or switches) and 1 MDI-X port (for connection to workstations or servers),
eliminating the need for crossover cables
• Both ports support full-duplex and half-duplex operation
• Total bandwidth of up to 200 Mbps (when full-duplex mode is used)
• Auto-senses transmission speed (10/100 Mbps)
• Uses adaptive cut-through switching (which dynamically changes among
standard cut-through, fragment free cut-through, and store-and-forward
depending on the error rate)
• Uses back pressure to eliminate frame loss by "blocking" traffic from end
stations or segments connected directly to the switch when its buffers fill
• Minimum latency of packet transmission (leading edge to leading edge) less
than 20 microseconds when using cut-through switching
• Uses "on the fly" cut-through technique to transport packets
• Transparent bridging function supported
• Address learning function to build the routing information database
• Operates at maximum packet filtering and forwarding rate

SwitcHub-2s User’s Guide
Introduction 1-5
• Provides frame filtering and forwarding functions for each port, which are
capable of filtering and forwarding 100% of all Ethernet packets at line
speed
• Provides a 160K byte buffer per port
• Routing table contains 4K entries per port to store node MAC addresses
• Uses fast hashing scheme to retrieve information from routing table when
making routing decisions
• An indicator panel for configuring the system or monitoring the overall
condition of the switch, including utilization, forwarding and collision rates

2-1
Chapter 2: Hardware Description
Accton’s SwitcHub-2s is a highly reliable network switch that complies with
IEEE 802.3 (10BASE-T) and IEEE 802.3u (100BASE-TX) specifications.
This switching hub delivers superior performance compared to the bridge and
router solution, and at a much lower cost. By confining local traffic to the
originating segment, and only forwarding cross-segment traffic to the other
port, this hub meets the requirements for Ethernet and IEEE 802.3 networks.
This chapter describes the hardware features of Accton’s SwitcHub-2s. For
easier management and control of the hub, familiarize yourself with the display
indicators, ports and configure button. Front and rear panel illustrations in this
chapter display the unit’s LED indicators, configure button and ports. Before
connecting any network device to the hub, read this chapter carefully.
Front Panel
The unit’s front panel provides a simple interface for configuring or monitoring
the switching hub. It includes a configure button, power indicator, display
mode indicators, port status indicators, and a statistical display for network
traffic as shown below.
Figure 2.1 The SwitcHub-2s Front Panel

SwitcHub-2s User’s Guide
2-2 Hardware Description
Configure Button
The Configure button is located on the left front panel. This button is used to
select the following configuration functions:
• System Performance (displays relative bandwidth utilization rate, forwarding
ratio, filtering ratio, and collision ratio for each port)
• Full/Half Duplex (sets port communication mode to full-duplex or half-
duplex operations)
• Diagnostics (tests the status of various system components)
To set system performance or diagnostic mode –
1. To start configuration use a "long press" on the Configure button. The
indicators will light up to show the selected configuration function. (Refer
to the related sections in this chapter and in Chapter 3 for complete details.)
2. To scan through the configuration functions use a "short press" on the
Configure button. (For information on how to select Full/Half duplex
communications, refer to Chapter 3.)
3. To accept and implement the current settings use a "long press" on the
Configure button.
F"Long press" means pressing the Configure button for more than 2 seconds and
then releasing it. While "Short press" means pressing the Configure button and
immediately releasing it. Also, note that if this button is not pressed within 10
seconds, the system returns to normal operation.

SwitcHub-2s User’s Guide
Hardware Description 2-3
SmartWatchLED Panel
The comprehensive LED array on the front panel (1) shows if the unit is
receiving power, (2) indicates the current display mode, (3) displays network
performance for each port, (4) indicates the status of port connections, and (5)
shows the result of diagnostic tests. The following figure shows the LED
indicators, each of which are described in the following sections.
Power
Display Mode Performance Indicators Port Status
Figure 2.2 SmartWatch LED Panel
Power
Color: Green
Label: Power
Function: Power indicator
LED Activity Condition Indication
STEADY LIGHT ON Unit is receiving power, CPU is running.
NO LIGHT OFF Power is disconnected, no power received.

SwitcHub-2s User’s Guide
2-4 Hardware Description
Statistical Display for System Performance
(Utilization, Forward, Filter & Collision Display Mode)
Display
Mode

Port 1 
Port 2 
Value 

Statistical
Indicators
Color: Green and Orange
Active LEDs: LED rows labeled 1 and 2
Function: Indicates a functional value for each port depending on the selected
display mode. (Refer to the Configure Button section earlier in this
chapter for instructions on how to select the display mode.)
Label (%) Color Indication
90+ Orange Util% Display Mode - The utilization percentage
70 Orange of LAN bandwidth.
50 Orange Forward% Display Mode - The percentage of packets
35 Green that are forwarded to another port.
20 Green Filter% Display Mode - The percentage of packets
10 Green filtered because destination is in the current segment.
5 Green Coll% Display Mode - The percentage of collisions
1 Green occurring out of the total packets transmitted by the port.
Utilization Display Mode - (Util%) The statistical indicators show the percentage of valid
data passing through each port compared to overall network bandwidth (updated
every 0.5 seconds). There are 8 LEDs representing the percentage of network
utilization. The corresponding LEDs light up to show that the utilization of LAN
bandwidth has reached this percentage. When active, these LEDs behave like a
stereo’s equalizer display.

SwitcHub-2s User’s Guide
Hardware Description 2-5
For example, if network utilization reaches 1%, the LED labeled 1% will light up.
However, if network utilization rises above 1% (e.g., 35%), the LED labeled 35
and all the other LEDs before it (i.e., 1, 5, 10 and 20) will also light up in rapid
succession. These indicators monitor the share of valid network frames handled
by each port within a 10Mbps or 100Mbps bandwidth, depending on the Ethernet
type currently selected on the back panel. They provide a quick way to monitor
the current traffic load relative to the network’s capacity.
Forward Display Mode (Forward%) - The statistical indicators show the percentage of
packets that must be forwarded by bridging hardware to the other port on the
switching hub (i.e., another LAN segment or connected workstation). When
viewing the Forward% indications, remember that under normal conditions, the
SwitcHub forwards 100% of all Ethernet packets that must be transferred among
the connected LAN segments at line speed.
Filter Display Mode (Filter%)- The statistical indicators show the percentage of
packets that must be filtered from the switching hub by bridging hardware
because the destination address is on the same segment connected to the
receiving port. When viewing the Filter% indications, remember that under
normal conditions, the SwitcHub filters 100% of all Ethernet packets that
belong to the local LAN segments at line speed.
Collision Display Mode (Coll%)- The statistical indicators show the percentage of packet
collisions occurring out of the total packets transmitted by the port. Collisions
occur when two or more devices connected to a hub attempt to transmit data
simultaneously on the network. When a collision occurs, devices pause and then
re-transmit after a pseudo-random wait period. Because wait periods differ among
devices, successive collisions become increasingly improbable.
The Collision LEDs assist the network manager in monitoring the percentage of
packet collisions occurring relative to the total packets transmitted by each port.
The collision indicators are labeled by row to indicate the percentage of
collisions encountered by the corresponding port. When collisions reach a

SwitcHub-2s User’s Guide
2-6 Hardware Description
level marked on the front panel display, the corresponding LED lights up. For
example, if packet collision reaches 1%, the LED labeled 1% will light up.
However, if collisions go beyond 1% (e.g., 30%), the LED labeled 30+% and all
the other LEDs before it (i.e., 1, 5, 10 and 20) also light up in rapid succession.
Setting the Communication Mode (Full/Half Duplex)
Color: Green
Active LEDs: Full/Half (Display Mode LED)
Full (Port Status LED)
Function: The communication mode can be set to either full-duplex or half-
duplex operation. Use the Configure button to light the Full/Half
Display Mode LED, indicating that the transmission mode may now
be set for the ports. Next set the Port Status LED for the correspond-
ing port in the LED column labeled Full as indicated below.
Full/Half (Display Mode LED) Condition Indication
STEADY LIGHT ON Transmission mode selection enabled.
NO LIGHT OFF Transmission mode selection disabled.
Full (Port Status LED) Condition Indication
STEADY LIGHT ON Port is set for full-duplex operation.
NO LIGHT OFF Port is set for half-duplex operation.
Notes: 1. Full-duplex mode is supported for both ports.
2. Full-duplex operation only applies to point-to-point access (e.g., when
attaching the SwitcHub to a workstation, server, or another switch). Repeater
hubs use a common collision domain for all communications, and therefore
cannot support full-duplex mode. When connecting theSwitcHub to a repeater
hub, use a standard cascaded connection set for half-duplex communications.