Transition Networks E-PSW-TX-02 User manual

TRANSITION NETWORKS’ POCKET SWITCH
TECHNICAL SPECIFICATIONS
Standards
IEEE 802.3, IEEE 802.3u
Dimension
4.75" X 5.75" X 1.0" (120mm x 146mm x 25mm)
Power Supply
NOTE: Replace power supply only with the equivalent input rating (see below) and
output rating (regulated 12VDC at 1.5 A).
TN PN Requirement Location
3507 240 volts, 50 hertz United Kingdom
3342 230 volts, 50 hertz Europe
3340 120 volts, 60 hertz USA/Canada/Mexico
3346 100 volts, 50-60 hertz Japan
3511 240 volts, 50 hertz Australia
3537 (with power cord: 3522) South Africa
Environment
Temperature: 0-50°C (32° to 122° F )
Humidity 10-90%, non condensing
Altitude 0-10,000 feet
Warranty
Lifetime
Transition Networks’
29
For assistance in installing, using, or
maintaining the TRANSITION Networks
Pocket Switch, contact TRANSITION
Networks Technical Support at:
[phone]
or contact your local distributor.
33015.B
(E-PSW-TX-02, E-PSW-FX-02)
Pocket Switch
Transition Networks’

100BASE-FX Cable and Connector Specifications
The physical characteristics of the 100BASE-FX cable must meet or exceed IEEE
802.3u 100BASE-FX specifications.
100BASE-FX CABLE SPECIFICATIONS
Fiber Optic Cable Recommended: 62.5 / 125 µm multimode fiber
Optional: 100 / 140 µm multimode fiber
85 / 125 µm multimode fiber
50 / 125 µm multimode fiber
Fiber Optic Transmitter Power:
Average power: -19.0 dBm
Fiber Optic Receiver Sensitivity:
Average sensitivity: -33.5 dBm
Bit error rate: ≤10-10
Maximum Cable Distance
Half-Duplex
Collision Domain: 412 meters (1375 feet)
Full-Duplex Link: 2000 meters (6500 feet)
100BASE-FX CONNECTOR CHARACTERISTICS:
One (1) transmit and one (1) receive ST connector.
Transition Networks’ Pocket Switch 28
CAUTION: RJ connectors are NOT INTENDED FOR
CONNECTION TO THE PUBLIC TELEPHONE
NETWORK. Failure to observe this caution could result
in damage to the public telephone network.
Compliance Information
UL Listed
C-UL Listed (Canada)
CISPR/EN55022 Class A
FCC Regulations
This equipment has been tested and found to comply with the limits for a class
A digital device, pursuant to part 15 of the FCC rules. These limits are
designed to provide reasonable protection against harmful interference when
the equipment is operated in a commercial environment. This equipment
generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a
residential area is likely to cause harmful interference, in which case the user
will be required to correct the interference at the user’s own expense.
Canadian Regulations
This digital apparatus does not exceed the Class A limits for radio noise for
digital apparatus set out on the radio interference regulations of the Canadian
Department of Communications.
European Regulations
Warning
This is a Class A product. In a domestic environment this product may cause
radio interference in which case the user may be required to take adequate
measures.
Copyright Restrictions
© 1997 TRANSITION Networks
All rights reserved. No part of this work may be reproduced or used in any
form or by any means – graphic, electronic, or mechanical – without written
permission from TRANSITION Networks.
Trademark Notice
All registered trademarks and trademarks are the property of their respective
owners.
Der Anschluss dieses Gerätes an ein öffentlickes
Telekommunikationsnetz in den EG-Mitgliedstaaten verstösst gegen die
jeweligen einzelstaatlichen Gesetze zur Anwendung der Richtlinie
91/263/EWG zur Angleichung der Rechtsvorschriften der
Mitgliedstaaten über Telekommunikationsendeinrichtungen
einschliesslich der gegenseitigen Anerkennung ihrer Konformität.

ETHERNET CABLE SPECIFICATIONS
10BASE-T/100BASE-TX Cable and Connector
Specifications
The physical characteristics of the 10BASE-T /100BASE-TX cable and
connectors must meet or exceed IEEE 802.3/802.3u specifications.
10BASE-T CABLE SPECIFICATIONS
Category 3 wire or better is required; category 5 wire (See 100BASE-TX)
is recommended. Either shielded twisted pair (STP) or unshielded
twisted pair (UTP) can be used. DO NOT USE FLAT OR SILVER SATIN
WIRE.
Category 3: Gauge 24 to 22 AWG
Attenuation 28 dB/1000’ @ 10 MHz
Impedance 100 Ω±10% @ 10 MHz
Maximum Cable Distance: 100 meters (330 feet)
100BASE-TX CABLE SPECIFICATIONS
Category 5 wire or better is required. Either shielded twisted pair (STP)
or unshielded twisted pair (UTP) can be used. DO NOT USE FLAT OR
SILVER SATIN WIRE.
Category 5: Gauge 24 to 22 AWG
Attenuation 20 dB/1000’ @ 10 MHz
Impedance 100 Ω±10% @ 10 MHz
Maximum Cable Distance: 100 meters (330 feet)
10BASE-T/100BASE-TX CONNECTOR CHARACTERISTICS:
The two active pairs in a 10BASE-T/100BASE-TX network are pins 1 & 2 and
pins 3 & 6. Use only dedicated wire pairs (such as blue/white & white/blue,
orange/white & white/orange) for the active pins. 10BASE-T /100BASE-TX cable
for unlike devices (such as hub to terminal device) must be configured as
straight through; 10BASE-T/100BASE-TX cable for like devices (such as hub to
hub or terminal device to terminal device) must be configured as crossover.
Transition Networks’ Pocket Switch
Table of Contents
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . 1
Transition Networks’ Pocket Switches . . . . . . . . . . . . . . . . . .1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
The Evolving Ethernet Network . . . . . . . . . . . . . . . . . . . . . . .2
Increasing Bandwidth by Segmenting 10BASE-T Collision
Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Doubling Bandwidth by Installing Full-Duplex . . . . . . . . . . .7
Increasing Bandwidth Ten-fold by Installing 100BASE-TX . . .9
Increasing Network Distance by Installing 100BASE-FX . . . .11
2 SITE CONSIDERATIONS. . . . . . . . . . . . . . . . . . . 11
3 INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . 14
Unpacking the Transition Networks’ Pocket Switch . . . . . . .14
Installing on Flat, Stable Surface . . . . . . . . . . . . . . . . . . . . .14
Setting DIP Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Installing Network Cable . . . . . . . . . . . . . . . . . . . . . . . . . . .16
The 5-Segment Rule (10BASE-T) . . . . . . . . . . . . . . . . . . . . . . .17
The 512-Bit Rule (100BASE-TX/100BASE-FX) . . . . . . . . . . . . .18
Straight-Through/Crossover Rule (10BASE-T/100BASE-TX) . . .19
Connecting Twisted-Pair Copper Cable to RJ-45 Connectors
(10BASE-T/100BASE-TX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Connecting Fiber Cable to TX/RX Connectors (100BASE-FX) . .21
Powering Transition Networks’ Pocket Switch . . . . . . . . . . .22
4 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . 24
Fault Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Technical Support Contact . . . . . . . . . . . . . . . . . . . . . . . . .24
WARRANTY STATEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
ETHERNET CABLE SPECIFICATIONS. . . . . . . . . . . . . . . . . . 27
TRANSITION NETWORKS’ POCKET SWITCH
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
i
27
Twisted
Pair #1
Twisted
Pair #2
Crossover Cable
Connectors for like devices
1
2
3
6
1
2
3
6
1
2
3
6
Twisted
Pair #1
Twisted
Pair #2
Straight Through Cable
Connectors for unlike devices
1
2
3
6

1. INTRODUCTION
This guide is intended for the system or network administrator
responsible for installing and monitoring a Transition Networks’ pocket
switch. A working knowledge of local area network (LAN) operations,
including familiarity with communications protocols used on
interconnected LANs, is assumed.
Transition Networks’ Pocket Switches
Transition Networks’ pocket switches (E-PSW-TX-02 and E-PSW-FX-02)
provide a smooth network migration from legacy Ethernet™ 10BASE-T
to Fast Ethernet 100BASE-TX or 100BASE-FX, supporting increasing
network demands through incremental upgrades to existing network
investments.
Features
• Supports a full Ethernet segment on each port
• Adheres to current and emerging IEEE802.3 and IEEE802.3u
Ethernet standards
• Provides two ports with selectable 10BASE-T or 100BASE-TX
• E-PSW-FX-02 provides one port with selectable 100BASE-FX
• Supports full- or half-duplex operation on both ports
• Provides selectable auto-negotiation for detecting and adapting
to line speed/operation mode of attached device on each port
• Provides wire-speed switching for same-speed transfers
• Provides packet buffers for high performance
• Supports self-learning of MAC addresses
Transition Networks’ Pocket Switch 26
1
Fiber
OR
UTP
UTP
The sole purpose of this remedy shall be provided the customer with the replacement or
repair of non-conforming goods in the manner described in this Warranty statement. This
exclusive remedy shall not be deemed to have failed of its essential purpose so long as TN is
willing and able to repair or replace the defective item(s) or refund the purchase price.
TN reserves the right to inspect products claimed to be defective under warranty either at the
customer’s location or at TN’s plant. TN assumes no liability for liability charges incidental
to the adjustment, service, repairing, removal or replacement of the product, or other costs,
or the expense of repairs made outside of its factory, except when made with TN’s prior
written consent. Additionally, Transition Networks reserves the right to charge for all testing
and shipping incurred, if after testing, a return is classified as “No Problem Found”.
TN’s total liability in connection with the products and their installation to all persons and
from all causes in the aggregate, whether in contract, tort, or strict liability, shall not exceed
the amount paid to TN for the product directly related to the alleged damage. However, in
no event shall TN have any liability to a customer or any third party for products
manufactures according to the customer’s specifications.
C. Return Procedure
The customer must follow this procedure for the return of defective items:
1. Locate the serial number(s) of the item(s) to be returned.
2. Determine the date the item(s) was received.
3. Contact Transition Networks Technical Support to determine if the problem can be
corrected on site.
If not, and the product is covered by warranty, then:
• Call the distributor directly or contact TN.
• Request a Return Material Authorization (RMA).
• Ship the item, prepaid in original packaging to Transition Networks at the above
address.
• Include the RMA number on the outside of the carton and/or on the Packing List.
• Include a copy of the RMA form.
• Include a copy of the original invoice or packing list (if possible) to expedite
processing.
• The item(s) may be shipped by the customer or the distributor.
• Transition Networks will repair or replace the unit, at TN’s discretion, and cover the
cost of the return freight to the distributor or to the customer, whichever requested
the RMA number.
If the item(s) was received more than five years ago, or if the item(s) is no longer covered by
warranty for other reasons, then:
• Call the distributor or contact TN.
• Request a Material Repair Authorization number (MRA).
• Ship the item(s), prepaid, in the original packaging to Transition Networks at the
above address.
• Include the MRA number on the outside of the carton add/or on the Packing List.
• Include a copy of the MRA form.
• Include a copy of the original invoice or packing list (if possible) to expedite processing.
• Only the customer (end-user) may send the items(s) to TN.
• TN will contact the customer after the item(s) have been received, inspected, and a
cost estimate of the repair determined.
• The repair charges may be billed, with customer’s approval, though the distributor, or
on a prepaid or C.O.D. basis directly to the customer. The charges will include the
cost of shipping.
The return authorization numbers are valid only for 90 days from the date issued.

The Evolving Ethernet Network
Installing one Transition Networks’ pocket switch alone improves
network performance. Installing additional Fast Ethernet equipment
(and, optionally, installing additional Transition Networks’ pocket
switches) can optimize network performance.
A network evolution from legacy Ethernet to legacy Ethernet and Fast
Ethernet that is based entirely on the Transition Networks’ E-PSW-FX-02
pocket switch might be:
Transition Networks’ Pocket Switch 2
25
10BASE-T Network
10 Mb/s
100 meters
10 Mb/s
100 meters
200 Mb/s
2000 meters
10 Mb/s
100 meters
Full Duplex Fiber
10BASE-T Network
10BASE-T Network
100 Mb/s
100 meters 100BASE-TX Network
10 Mb/s
100 meters
10BASE-T Network
Warranty Statement
A. Five Year Warranty
Transition Networks, Inc. (TN) warrants, for a period of five years, that TN products (with
the exception of power supplies and fans that TN warrants for two years) will be free from
defects in materials and workmanship, and will be in conformity with TN’s specifications.
TN’s warranty on products manufactured by or assembled for TN in accordance with a
customer’s specifications, is a five-year warranty that the goods conform to such
specifications.
The warranty is invalidated if the goods have been subject to alterations, misuse, accident,
Acts of God (e.g., damage by floods, lightning strikes, Etc.), tampering, improper
maintenance, improper maintenance, improper installation, or abuse. If the user is unsure
about the proper means of installing or using the equipment, contact TN’s free Technical
Support or Network Design Services, which can be reached by:
Telephone 1.800.LAN.WANS or 612.941.7600
Fax [phone]
E-mail [email protected]
Internet http://www.transition.com
THE ABOVE WARRANTY IS EXCLUSIVE AND EXTENDS ONLY TO PRODUCTS
ASSEMBLED BY TRANSITION NETWORKS, INC. TO THE EXTENT PERMITTED BY LAW,
TN DOES NOT MAKE AND DISCLAIMS ALL OTHER WARRANTIES, EXCEPT TITLE,
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY OF
DESCRIPTION, MERCHANTIBILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-
INFRINGEMENT, AND ANY WARRANTY BASED UPON PRIOR WRITTEN OR ORAL
REPRESENTATIONS REGARDING SUCH PRODUCTS MADE BY TN, ITS EMPLOYEES,
AGENTS, OR REPRESENTATIVES.
B. Limitations and Exclusions
If the customer believes any goods sold by TN are defective and within the warranty period,
the following general procedure will be followed:
1. Locate the serial number and delivery date of the item(s).
2. Notify TN within the warranty period.
3. TN will promptly issue a return authorization form for the goods.
4. Upon receiving the form, the customer will promptly return the item(s) at customers
own expense, shipped prepaid, to the distributor from which it was purchased, or
directly to TN.
TN will only accept goods for return if the following conditions have been met:
1. A return form is obtained from TN.
2. The freight charges have been prepaid by the customer.
3. Goods are re-packed in their original packaging.
If under warranty TN shall, at its option, (1) repair the goods free of charge (2) replace the
goods free of charge, or (3) accept the return of the item(s) and credit the current price to
the reseller (within 90 days of purchase), or (4) if the goods are not under warranty, will
repair the item(s) at a minimum charge of USD $200 (two hundred U.S. dollars) per item.
THIS IS THE EXCLUSIVE REMEDY FOR ANY BREACH OF WARRANTY. IN NO EVENT
SHALL TRANSITION NETWORKS BE LIABLE FOR SPECIAL, INDIRECT, INCIDENTAL OR
CONSEQUENTIAL DAMAGES OF ANY KIND, WHETHER FOR BREACH OF ANY
CONDITION OF SALE, FOR NEGLIGENCE, ON THE BASIS OF STRICT LIABILITY,
CONTRACT, OR OTHERWISE AND IRRESPECTIVE OF WHETHER TN IS INFORMED BY
CUSTOMER OF THE POSSIBILITY OF SUCH DAMAGES IN ADVANCE OF THIS SALE.

Network Flexibility
The Transition Networks’ pocket switch can assist a network
administrator in maintaining existing resources as the network evolves
from shared legacy 10Mb/s Ethernet to switched 100Mb/s Fast Ethernet
because a pocket switch can function as :
• A 2-port bridge in the legacy 10BASE-T environment
• A connection between the legacy 10BASE-T environment and
the evolving Fast Ethernet 100BASE-TX /100BASE-FX
environment
• A 2-port bridge in the Fast Ethernet 100BASE-TX /100BASE-FX
environment.
Standards-Based
Transition Networks’ pocket switches are designed and built according
to accepted and evolving Ethernet standards. The IEEE 802.3 Carrier
Sense Multiple Access with Collision Detection (CSMA/CD) Access
Method and Physical Layer Specifications, which applies to 10BASE-T,
has been adopted by the International Organization for Standardization
(ISO). IEEE 802.3u is the extension of IEEE 802.3 to 100BASE-X.
Protocol Compatible
As devices functioning on the OSI MAC layer, Transition Networks’
pocket switches are protocol independent and therefore totally
compatible with IEEE 802.3, IEEE 802.3u, TCP/IP, NetWare, DECnet
and XNS protocols. No software installation is required. Protocol
compatibility allows cost-effective network migration with maximum
use of existing equipment, cabling infrastructure, network management
systems, and MIS expertise.
Pocket Switch Operation
The Transition Networks’ pocket switch is an Ethernet network device
integrated into the legacy Ethernet network that adapts selectively to the
Fast Ethernet network by examining all incoming data packet frames for
the destination address and quickly determining the appropriate output
port and mode (half-duplex or full-duplex) for the packet.
5. MAINTENANCE
WARNING: DO NOT, UNDER ANY CIRCUMSTANCES, attempt to
repair the Transition Networks’ pocket switch. Failure to observe this
warning could result in personal injury or death from electrical shock.
NOTE: Failure to observe the above warning will immediately void the
warranty.
Fault Isolation
1. Is the power LED on the switch illuminated?
NO• Is the power adapter the proper type of voltage and cycle
frequency for the AC outlet?
• Is the power adapter properly installed in the switch and in
the outlet?
• Contact Technical Support.
YES• Proceed to step 2.
2. Is the Link LED illuminated on a port with twisted-pair installed?
NO• Check UTP cables for proper connection/pin assignment.
• Contact Technical Support.
YES• Proceed to step 3.
3. Is the Link LED illuminated on a port with fiber installed?
NO• Check fiber cables for proper connection.
• Verify that TX and RX cables are connected to RX and TX
ports, respectively, on 100BASE-FX device.
• Refer to Tech Tips available at: http://www.transition.com
• Contact Technical Support.
YES• Contact Technical Support.
Technical Support Contact
[phone]/(800-LAN-WANS
Transition Networks’ Pocket Switch 24
3

4. OPERATION
The Transition Networks’ pocket switch requires no operator
intervention beyond occasionally monitoring LED status indicators.
POWER Steady green LED indicates connection to external
AC power.
NOTE: The port LED indicators provide separate data for each port.
100 (MB/S) Steady green LED indicates that port transmits and
receives at 100 Mb/s.
L(INK) Steady green LED indicates port link connection is
active.
H(ALF) D(UPLEX) Steady green LED indicates port sends and
receives data simultaneously over same cable.
R(ECEIVE) Blinking green LED indicates port is receiving data.
Connectors, Switches, and Indicators
Connectors
ON PORT 1 One (1) 10/100Mb/s RJ-45 twisted-pair connector
AND (E-PSW-FX-02 only) one (1) 100Mb/s ST fiber
connector pair
ON PORT 2 One (1) 10/100Mb/s RJ-45 twisted-pair connector
LED Indicators
POWER Steady green LED indicates connection to external
AC power.
NOTE: The port LED indicators provide separate data for each port.
100 (MB/S) Steady green LED indicates that port transmits and
receives at 100 Mb/s; dark LED indicates 10 Mb/s.
L(INK) Steady green LED indicates active port link
connection.
H(ALF) D(UPLEX) Steady green LED indicates half-duplex mode;
dark LED indicates full-duplex mode.
R(ECEIVE) Blinking green LED indicates port is receiving
data.
Switches (at surface opposite connectors)
DIP Allows selection, for each port, of operating speed
and mode or selection of Auto-Negotiation.
RESET Resets hardware to initial operating condition.
Transition Networks’ Pocket Switch 4
23
Port 1 LED Indicators
Port 2 LED Indicators
Power LED Indicator
Port 1 10BASE-T/100BASE-TX Connector
Port 1 100BASE-FX Connector
Port 2 10BASE-T/100BASE-TX Connector
Port 1 LED Indicators
Port 2 LED Indicators
Power LED Indicator

Increasing Bandwidth by Segmenting 10BASE-T
Collision Domain
The Transition Networks’ pocket switch adapts to the fact that each
Ethernet network device (station) is connected independently to the
shared Ethernet signaling system, called the network medium. Each
station transmits serially over the shared medium to every other
attached station. Access to the medium is determined by a medium
access control (MAC) mechanism in the Ethernet interface of the station.
The Ethernet CSMA/CD Protocol
The Ethernet medium access control mechanism is based on the Carrier
Sense Multiple Access with Collision Detection (CSMA/CD) protocol.
Under the CSMA/CD protocol, each station waits until there is no signal
on the channel (Carrier Sense) and then begins transmitting (Multiple
Access). Since signals take a finite time to travel from one end of an
Ethernet network to the other, the first bits of a transmitted frame do not
reach all parts of the network simultaneously. Two stations could sense
that the network is idle and start transmitting frames simultaneously.
When this happens, the Ethernet system senses the signal "collision",
stops the transmission, and resends the frames (Collision Detection).
Thus, a collision domain is a single CSMA/CD network in which a
collision will occur if two network stations transmit at the same time.
Ethernet Switching
The Transition Networks’ pocket switch can improve network
performance by breaking the large CSMA/CD collision domain into two
separate collision domains (called segments). Network segmentation is
achieved by regulating the number of data signals sent among stations.
Since the first two fields in an Ethernet data packet carry 48-bit source
and destination addresses, the pocket switch scans the destination
address on each packet header received on a port, searches a dynamic
internal MAC routing table, and forwards the packet only if the data is
intended for a station beyond the local collision domain. If the data is
intended for a station on the collision domain from which the packet
was received, the pocket switch discards (filters) the packet, since any
signal on the local segment already has been received by all stations on
that segment. Baseline network performance also is improved because
switches do not forward collision signals or error packets from one
collision domain to another.
Powering Transition Networks’ Pocket Switch
To power ON the Transition Network’s pocket switch:
1. Locate the power receptacle on the back of the Transition
Network’s pocket switch
2. Connect the Transition Network’s pocket switch power
connector end of the power supply adapter to the power
receptacle on the back of the Transition Network’s pocket
switch.
3. Connect the external power connector end of the power supply
adapter to external AC power.
NOTE: After the power supply adapter is connected to the Transition
Network’s pocket switch and to external power, the green Power LED
is illuminated.
Transition Networks’ Pocket Switch 22
5

Installing Network Cable(continued)
Connecting Fiber Cable to TX/RX Connectors
(100BASE-FX)
Effective cable distances are determined by ambient RF noise and by
signal loss in the cable. Since fiber has a low signal loss/meter and is
invulnerable to RF noise, fiber can be used to extend distances.
OPTICAL POWER LOSS BUDGET
An 11dB loss budget, as measured by a fiber optic power meter, is
allowed per link. A typical performance rating for standard grade fiber
operating at 1350 nm is approximately 1dB-2dB loss per 1000 meters of
cable. Approximately 0.5dB-2.0dB loss per connection point is typical,
depending on how well the connection has been made.
FAST ETHERNET COLLISION DOMAIN
NOTE: Installing full-duplex fiber cable avoids collision domain
considerations and extends distances up to 2000 meters.
A Fast Ethernet collision domain can have ONLY ONE CLASS I repeater
OR TWO CLASS II repeaters.
Refer to the 512-Bit Rule (page18) regarding Fast Ethernet collision
domains before installing half-duplex 100BASE-FX cable (≤415 meters).
INSTALLING CABLE
To install 100BASE-FX cable:
1. Locate or build 100BASE-FX cables with the following
characteristics:
• 803.2u compliant (See page 28)
• male ST transmit and receive fiber connectors installed at
both cable ends.
2. At Transition Networks’ pocket switch, connect transmit cable
connector at one end of fiber cable to ST connector marked
with an “outbound” arrow; connect receive cable connector to
ST connector marked with an “inbound” arrow.
3. Connect cable installed at transmit (TX) connector of Transition
Networks’ pocket switch at receive (RX) connector of device at
other end; connect cable installed at receive (RX) connector at
transmit (TX) connector of device at other end of fiber cable.
When installed in a legacy 10BASE-T Ethernet network, the Transition
Networks’ pocket switch segments network traffic on the original
10Mb/s Ethernet collision domain into two distinct 10Mb/s Ethernet
collision domains.
Ideally, the system administrator defines collision domain segments so
that most traffic on each segment is local to the segment.
MAC Address Table
The dynamic internal routing table of the Transition Networks’ pocket
switch provides self learning capabilities for up to 8192 MAC addresses
of incoming and outgoing packets. Once a network node address is
stored in the MAC address table, data packets addressed to that node
are sent directly. Packets whose destination address is on the same
CSMA/CD collision domain as the packet source address are discarded
by the pocket switch. NOTE: The MAC address table is volatile and
disappears when the pocket switch is powered off or reset.
Transition Networks’ Pocket Switch 6
21
C
S
M
A/CD
Col
lisio
n
Do
m
ai
n
C
S
M
A/
C
D
C
ol
lis
ion
D
o
m
a
i
n
C
S
M
A/
C
D
C
ol
lis
ion
D
o
m
a
i
n
100 meters
10 Mb/s
100 meters
10 Mb/s
Install Transition Networks' Pocket Switch
To Divide Repeater Stack Collision Domain
100 meters
Existing 10 Mb/s Network

Doubling Bandwidth by Installing Full-Duplex
NOTE: The 10BASE-T specification requires two dedicated twisted
copper wire pairs for data transmission and reception. This allows twisted
pair copper cable to be used either in half-duplex or full-duplex mode.
Legacy CSMA/CD Ethernet is Half-Duplex
Legacy Ethernet is a half-duplex communications system in which data
can be transferred in both directions but in which, at any given time, a
station is either transmitting or receiving. (On the original Ethernet
physical medium (coaxial cable) the same wire was used both for
transmission and reception.) With the current 10BASE-T physical media
(twisted pair), separate copper wire pairs are used for transmission and
for reception. Each station transmits to all stations and receives from all
stations. Since many devices share the medium, a device at the end of a
half-duplex Ethernet link listens for other transmissions or for collisions
when sending data, using the CSMA/CD protocol to prevent multiple
simultaneous transmissions on the medium.
Microsegmented Ethernet Link is Full-Duplex
Installing full-duplex allows the station attached to the Transition
Networks’ pocket switch to both transmit and receive at the same time.
In the microsegmented full-duplex switched Ethernet environment,
each station is connected to one dedicated switch port. Only the
attached station ever transmits to the switch (using the Transmit pair of
the cable), and only the switch ever transmits to the attached station
(using the Receive pair of the cable). There is never any contention for
the use of the medium, as in a standard half-duplex Ethernet
environment. Instead, both the station and the switch transmit at will,
using both directions simultaneously.
One advantage of this approach is that the full-duplex link can
theoretically provide twice the bandwidth of normal (half-duplex)
Ethernet. Since there are only two devices on a full-duplex link, the link
is not attempting to create a shared Ethernet channel capable of
supporting multiple devices. Therefore, there is no need to adhere to
the original Ethernet medium access control system. With no need to
use the CSMA/CD medium access control mechanism to share the
signal channel with multiple stations, a device at the end of a full-
duplex Ethernet link does not have to listen for other transmissions or
for collisions when sending data.
Connecting Twisted-Pair Copper Cable to RJ-45 Connector
(10BASE-T/100BASE-TX)
Though Category 3 cable is adequate for the 10BASE-T installation,
Category 5 cable is strongly recommended because Category 3 cable
can NOT be used for a later upgrade to 100BASE-TX. (Refer to the
cable specifications on page 27.)
10BASE-T AND THE ETHERNET COLLISION DOMAIN
• Refer to the 5-Segment Rule (page 17) before installing half-
duplex 10BASE-T cable.
• Installing full-duplex twisted-pair cable avoids collision
domain considerations; distances remain ≤100 meters.
100BASE-TX AND THE FAST ETHERNET COLLISION DOMAIN
• Refer to the 512-Bit Rule (page 18) before installing half-duplex
100BASE-TX cable.
• Installing full-duplex twisted-pair cable avoids collision
domain considerations; distances remain ≤100 meters.
• A Fast Ethernet collision domain can have ONLY ONE CLASS I
repeater OR ONLY TWO CLASS II repeaters.
INSTALLING CABLE
To install 10BASE-T or 100BASE-TX cable:
1. Locate or build 10BASE-T or 100BASE-TX cables with the
following characteristics:
• 803.2 (10BASE-T) or 803.2u (100BASE-TX) compliant (See
pages 27, 28)
• correct Straight-through or Crossover cable configuration
for site installation (See page 19)
• male RJ-45 plug connectors installed at both cable ends.
2. Connect male RJ-45 plug connector at one end of 10BASE-T or
100BASE-TX cable to Transition Networks’ pocket switch RJ-45
jack connector.
3. Connect male RJ-45 plug connector at other end of 10BASE-T
or 100BASE-TX cable to network device RJ-45 jack connector.
Transition Networks’ Pocket Switch 20
7