Cabletron Systems Switch 24 User Manual

STH-22/-24/-42/-44  
STACKABLE TOKEN RING HUB  
USERS GUIDE  
CABLETRON SYSTEMS, P. O. Box 5005, Rochester, NH 03866-5005  
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NOTICE  
FCC Notic e  
This device complies with Part 15 of the FCC rules. Operation is subject to the  
following two conditions: (1) this device may not cause harmful interference,  
and (2) this device must accept any interference received, including  
interference that may cause undesired operation.  
NOTE: 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 uses,  
generates, and can radiate radio frequency energy and if not installed in  
accordance with the operators manual, may cause harmful interference to  
radio communications. Operation of this equipment in a residential area is  
likely to cause interference in which case the user will be required to correct the  
interference at his own expense.  
WARNING: Changes or modifications made to this device which are not  
expressly approved by the party responsible for compliance could void the  
users authority to operate the equipment.  
DOC Notic e  
This digital apparatus does not exceed the Class A limits for radio noise  
emissions from digital apparatus set out in the Radio Interference Regulations  
of the Canadian Department of Communications.  
Le présent appareil numérique német pas de bruits radioélectriques dépassant  
les limites applicables aux appareils numériques de la class A prescrites dans  
le Règlement sur le brouillage radioélectrique édicté par le ministère des  
Communications du Canada.  
iv  
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NOTICE  
CABLETRON SYSTEMS, INC.  
PROGRAM LICENSE AGREEMENT  
IMPORTANT: Before utilizing this product, carefully read this License  
Agreement.  
This document is an agreement between you, the end user, and Cabletron  
Systems, Inc. (Cabletron) that sets forth your rights and obligations with  
respect to the Cabletron software program (the Program) contained in this  
package. The Program may be contained in firmware, chips or other media. BY  
UTILIZING THE ENCLOSED PRODUCT, YOU ARE AGREEING TO  
BECOME BOUND BY THE TERMS OF THIS AGREEMENT, WHICH  
INCLUDES THE LICENSE AND THE LIMITATION OF WARRANTY AND  
DISCLAIMER OF LIABILITY. IF YOU DO NOT AGREE TO THE TERMS OF  
THIS AGREEMENT, PROMPTLY RETURN THE UNUSED PRODUCT TO  
THE PLACE OF PURCHASE FOR A FULL REFUND.  
CABLETRON SOFTWARE PROGRAM LICENSE  
1. LICENSE. You have the right to use only the one (1) copy of the Program provided  
in this package subject to the terms and conditions of this License Agreement.  
You may not copy, reproduce or transmit any part of the Program except as  
permitted by the Copyright Act of the United States or as authorized in writing by  
Cabletron.  
2. OTHER RESTRICTIONS. You may not reverse engineer, decompile, or  
disassemble the Program.  
3. APPLICABLE LAW. This License Agreement shall be interpreted and governed  
under the laws and in the state and federal courts of New Hampshire. You accept  
the personal jurisdiction and venue of the New Hampshire courts.  
v
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NOTICE  
EXCLUSION OF WARRANTY  
AND DISCLAIMER OF LIABILITY  
1. EXCLUSION OF WARRANTY. Except as may be specifically provided by  
Cabletron in writing, Cabletron makes no warranty, expressed or implied,  
concerning the Program (including Its documentation and media).  
CABLETRON DISCLAIMS ALL WARRANTIES, OTHER THAN THOSE  
SUPPLIED TO YOU BY CABLETRON IN WRITING, EITHER EXPRESS OR  
IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF  
MERCHANTABLITY AND FITNESS FOR A PARTICULAR PURPOSE, WITH  
RESPECT TO THE PROGRAM, THE ACCOMPANYING WRITTEN MATERIALS,  
AND ANY ACCOMPANYING HARDWARE.  
2. NO LIABILITY FOR CONSEQUENTIAL DAMAGES. IN NO EVENT SHALL  
CABLETRON OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES  
WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS  
OF BUSINESS, PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS  
INFORMATION, SPECIAL, INCIDENTAL, CONSEQUENTIAL, OR RELIANCE  
DAMAGES, OR OTHER LOSS) ARISING OUT OF THE USE OR INABILITY TO  
USE THIS CABLETRON PRODUCT, EVEN IF CABLETRON HAS BEEN  
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. BECAUSE SOME  
STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY  
FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES, OR ON THE DURATION  
OR LIMITATION OF IMPLIED WARRANTEES IN SOME INSTANCES THE  
ABOVE LIMITATIONS AND EXCLUSIONS MAY NOT APPLY TO YOU.  
vi  
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NOTICE  
UNITED STATES GOVERNMENT  
RESTRICTED RIGHTS  
The enclosed product (a) was developed solely at private expense; (b) contains  
restricted computer software” submitted with restricted rights in accordance  
with Section 52227-19 (a) through (d) of the Commercial Computer Software -  
Restricted Rights Clause and its successors, and (c) in all respects is  
proprietary data belonging to Cabletron and/or its suppliers.  
For Department of Defense units, the product is licensed with Restricted  
Rights” as defined in the DoD Supplement to the Federal Acquisition  
Regulations, Section 52.227-7013 (c) (1) (ii) and its successors, and use,  
duplication, disclosure by the Government is subject to restrictions as set forth  
in subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer  
Software clause at 252.227-7013. Cabletron Systems, Inc., 35 Industrial Way.  
Rochester, New Hampshire 03866  
vii  
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CONTENTS  
CONTENTS  
CHAPTER 1 INTRODUCTION  
1.1 Using This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1  
1.2 STH Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1  
1.2.1 LANVIEW LEDs . . . . . . . . . . . . . . . . . . . . . . . . . 1-3  
1.2.2 TCU Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3  
1.2.3 Automatic Beacon Recovery Process . . . . . . . . 1-4  
1.2.4 Support for Passive MAU Workgroups . . . . . . 1-4  
1.3 Related Manuals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5  
1.4 Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7  
CHAPTER 2 REQUIREMENTS & SPECIFICATIONS  
2.1 General Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . 2-1  
2.2 Cable Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3  
2.3 UTP Cabling Specifications . . . . . . . . . . . . . . . . . . . . . . 2-3  
2.3.1 UTP Cable Categories . . . . . . . . . . . . . . . . . . . . . 2-3  
2.3.2 UTP Lobe Lengths . . . . . . . . . . . . . . . . . . . . . . . . 2-5  
2.4 STP Cabling Specifications . . . . . . . . . . . . . . . . . . . . . . . 2-5  
2.4.1 STP Cable Categories. . . . . . . . . . . . . . . . . . . . . . 2-6  
2.4.2 STP Lobe Lengths. . . . . . . . . . . . . . . . . . . . . . . . . 2-6  
2.5 TCU Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7  
2.6 Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 2-8  
2.6.1 Ring Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8  
2.6.2 Ring Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9  
2.6.3 Power Supply Requirements . . . . . . . . . . . . . . . 2-9  
2.6.4 Environmental Requirements . . . . . . . . . . . . . 2-10  
2.6.5 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10  
2.6.6 Physical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10  
ix  
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CONTENTS  
CHAPTER 3 INSTALLATION  
3.1 Unpacking the STH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1  
3.2 Installing the STH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1  
3.2.1 Rack Mount or Wall Mount Hardware. . . . . . . 3-1  
3.2.2 Adding the STH to a Stack . . . . . . . . . . . . . . . . . 3-2  
3.2.3 Attaching the Strain Relief Bracket . . . . . . . . . . 3-3  
3.2.4 Rack-Mounting the STH . . . . . . . . . . . . . . . . . . . 3-3  
3.2.5 Wall-Mounting the STH . . . . . . . . . . . . . . . . . . . 3-4  
3.2.6 Free-Standing Installation. . . . . . . . . . . . . . . . . . 3-6  
3.2.7 Connecting the STH to the Power Source . . . . 3-7  
3.2.8 Attaching Network Cabling to TCU Ports . . . . 3-7  
3.3 Finishing the Installation . . . . . . . . . . . . . . . . . . . . . . . . 3-8  
CHAPTER 4 TROUBLESHOOTING  
4.1 LANVIEW LED Signals . . . . . . . . . . . . . . . . . . . . . . . . . 4-1  
4.2 Trouble Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1  
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CHAPTER 1  
INTRODUCTION  
Welcome to the Cabletron Systems STH-22/-24/-42/-44 Stackable Token  
Ring Hub User’s Guide. The STH (Stackable Token Ring Hub) is a non-  
intelligent hub designed to provide expanded connectivity for Cabletron  
Systems’ STHi intelligent hubs and Cabletron Systems MicroMMAC  
intelligent hubs. This manual provides installation instructions and  
reference information for STH models 22, 24, 42, and 44.  
Note: The term STH is used throughout this manual when describing  
features and functions that are common to the above listed STH models.  
Read through this manual completely to familiarize yourself with its  
content and to gain an understanding of the features and capabilities of  
the STH. A general working knowledge of IEEE 802.5 Token Ring data  
communications networks and their physical layer components will be  
helpful when installing the STH.  
Chapter 1, INTRODUCTION, outlines the contents of this manual,  
briefly describes STH features, and concludes with a list of related  
manuals.  
Chapter 2, REQUIREMENTS & SPECIFICATIONS, describes  
installation requirements, network guidelines, and STH operating  
specifications.  
Chapter 3, INSTALLATION, contains instructions for installing the STH.  
Chapter 4, TROUBLESHOOTING, describes how to use the LANVIEW  
LEDs to troubleshoot network problems.  
1.2 STH Ove rvie w  
The STH is a non-intelligent hub which provides expanded connectivity  
for Cabletron Systems’ STHi intelligent hubs and Cabletron Systems  
MicroMMAC intelligent hubs. Each STH added to an intelligent hub‘s  
managed stack increases the LAN’s connectivity by 12 or 24 Trunk  
Page 1-1  
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STH Ove rvie w  
Connector Ports (TCUs) for connections to stations and other network  
devices.  
TOKEN RING HUB with LANVIEW®  
HubSTACK  
STH-24  
SUPPORTING 100 OHM UTP CABLE  
24X 23X 22X 21X 20X 19X  
18X 17X 16X 15X 14X 13X  
PWR  
16Mb/s  
4M  
16M  
STACK  
SPEED  
6X  
5X  
4X  
3X  
2X  
1X  
12X 11X 10X  
9X  
8X  
7X  
TOKEN RING HUB with LANVIEW®  
SN  
STH-24  
RESERVED  
STACK  
Figure 1-1. Front and Back Views of the STH-24  
Up to four STH hubs can be linked to the same intelligent hub, bringing  
the total direct connectivity potential to 120 managed TCU ports in the  
stack. Intelligent hubs serve as the logical “top” of the stack and provide  
full frame and error statistics for the collective stack, for each individual  
device, and for each port. Hubs can be added to and removed from the  
stack without powering-down any of the devices involved.  
Cabletron’s HubSTACK Interconnect cables, Part Number 9380141, are  
needed when stacking hubs.  
The STH fully conforms to IEEE 802.5Token Ring specifications for  
connectivity to Token Ring equipment. STH hubs offer:  
support for Cabletron Systems’ Automatic Beacon Recovery  
Process (ABRP),  
Multiple Ring Out connectivity for Passive MAU workgroups,  
automatic speed fault protection,  
active filtering, re-timing, and repeating circuitry on all ports,  
and LANVIEW LEDs for at-a-glance” diagnostic monitoring.  
The STH does not have management capability and is not intended to be  
used as a stand-alone device. Management must be provided by a  
Cabletron Systems intelligent hub, either the STHi Stackable Token Ring  
Hub with Intelligence or the MicroMMAC intelligent hub.  
Page 1-2  
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LANVIEW LEDs  
1.2.1 LANVIEW LEDs  
Cabletron Systems’ LANVIEW Status Monitoring and Diagnostics  
System is a troubleshooting tool. Conveniently located on the front panel,  
LANVIEW LEDs help the user to quickly identify power failures,  
beaconing conditions, cable faults, and link problems.  
Refer to Section 4.1, LANVIEW LED Signals for more information on the  
LANVIEW LED visual status monitoring system.  
1.2.2 TCU Ports  
Each STH, depending on the STH model (see Table 1-1. ), is equipped  
with 12 or 24 TCU ports, each fitted with a female RJ45 modular  
connector jack to support the attachment of either STP (shielded twisted  
pair) or UTP (unshielded twisted pair) cabling with RJ45 connector plugs.  
Models that support STP cabling use RJ45 connectors that provide a  
grounded connection for the cabling shield.  
Table 1-1. Port and Media List for STH Models  
STH-22  
STH-24  
STH-42  
STH-44  
12 - Unshielded RJ45 ports  
24 - Unshielded RJ45 ports  
12 - Shielded RJ45 ports  
24 - Shielded RJ45 ports  
Each TCU port on the STH is internally defaulted to operate as a lobe  
interface to support the insertion of a Token Ring station into a ring.  
However, each TCU port may also be reconfigured, via the intelligent  
hub’s Local Management (LM) application, to function as a Ring Out port  
to support the connection of non-intelligent, passive MAU (Multi-Station  
Access Unit) workgroups. See Section 1.2.4, Support for Passive MAU  
Workgroups.  
Ring Sp e e d Fa ult Prote c tion  
STH hubs also provide Ring Speed Fault Protection on each TCU port to  
protect against beaconing conditions caused by stations inserted at the  
Page 1-3  
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Autom a tic Be a c on Re c ove ry Proc e ss  
wrong ring speed. If a ring speed mismatch is detected, the STH disables  
the port to keep the misconfigured station isolated from the ring and  
provides a simple visible LED signal (blinking red at the port’s LED) to  
indicate to the user that Speed Fault Protection has disabled the port. The  
port remains disabled until the ring speed mismatch condition is  
removed or resolved.  
Ac tive Circ uitry  
On each TCU port, STH hubs provide active circuitry which filters,  
equalizes, and amplifies all received signals before transmitting them to  
the next point on the ring. The result is enhanced signal integrity and  
extended maximum station lobe cable distances.  
Da ug hte r Boa rd Up g ra d e Kit  
Both the STH-22 and the STH-42 can be upgraded to 24 ports using the  
following daughter board upgrade kits:  
TR-UTP-UGKT for STH-22.  
TR-STP-UGKT for STH-42.  
1.2.3 Autom a tic Be a c on Re c ove ry Proc e ss  
To guard against interruptions in network operations due to beaconing  
conditions, the STH supports Cabletron Systems’ advanced Automatic  
Beacon Recovery Process which automatically partitions problematic  
lobes from the ring, allowing the rest of the ring to continue operating.  
(ABRP engages even before the IEEE standard beacon recovery process  
begins and is able to treat conditions beyond the scope of the IEEE  
process.) It is the stack’s intelligent hub that actually executes the ABRP  
algorithm. The intelligent hub also checks partitioned lobes periodically  
and re-enables them automatically once they have recovered.  
1.2.4 Sup p ort for Pa ssive MAU Workg roup s  
Whereas a station signals a TCU to open its interface by sending a  
phantom current down its lobe cable, a passive Multi-Station Access Unit  
can not provide phantom current. A TCU Ring Out port is therefore  
configured to ignore the absence of phantom current in the connecting  
cable and to look instead for the presence of data bits to determine link  
status.  
Page 1-4  
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Re la te d Ma nua ls  
By default, each of the STH hub’s TCU ports is configured to its STN  
(station) setting to support concentrator lobe connections to stations.  
Through Local Management, any TCU port may be reconfigured to its  
RO (Ring Out) setting to support connections to passive MAU (Multi-  
Station Access Unit) workgroups.  
Im p rove d Prote c tion from Be a c oning  
passive MAUs because Multiple Ring Out TCUs allow for the separate  
attachment of each MAU. Rather than daisy-chaining MAUs together as a  
single entity and risking their collective isolation in case of beaconing, the  
user can now attach each MAU individually, reducing the number of  
MAU ports that are at risk of collective isolation in case of beaconing on  
the ring; ABRP is able to bypass individually connected MAUs on an  
individual rather than collective basis. See Figure 1-2.  
No Conne c tion Re d und a nc y  
The STH hub’s Ring Out TCU configuration does not provide for the  
MAU’s redundant connection to the ring. In the common configuration, a  
MAU chain is dual-attached to the Token Ring LAN via both a Ring Out  
cable and a Ring In cable. Using a TCU port, however, each passive MAU  
workgroup is physically connected to the hub in the same manner as a  
station—by a single cable—and therefore is not provided a backup path  
between the MAU and the Token Ring network. Only the dual  
attachment of Ring In and Ring Out cables can provide a backup path.  
This level of connectivity must be provided by a dedicated pair of Ring In  
/ Ring Out ports such as those available on the intelligent hub.  
1.3 Re la te d Ma nua ls  
Use the STHi User’s Guide (PN 9031390) and the MicroMMAC-xxT  
User’s Guide (PN 9031320) to supplement the procedures and other  
technical data provided in this manual.  
Page 1-5  
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Re la te d Ma nua ls  
DAISY-CHAIN MAU CONFIGURATION  
When MAUs are daisy-chained,  
they are connected as single collective entity.  
The entire chain must be bypassed  
to isolate the hub from a single beaconing station.  
All stations lose connection if beaconing occurs on any station.  
Ring  
Out  
Ring  
In  
(8 Stations)  
(8 Stations)  
(8 Stations)  
(8 Stations)  
Ring  
Out  
Ring  
Out  
Ring  
In  
Ring  
In  
Ring  
Out  
Ring  
In  
Ring  
Out  
Ring  
In  
Hub with  
Ring In / Ring Out  
RING OUT TCU MAU CONFIGURATION  
When each MAU is individually connected to the STH hub,  
only one MAU must be bypassed  
to isolate the hub from a beaconing MAU station.  
The 8 stations on that MAU still go down,  
but the remaining MAUs and their stations stay operational.  
Ring  
(8 Stations)  
In  
Ring  
Out  
Ring  
In  
(8 Stations)  
(8 Stations)  
(8 Stations)  
Ring  
Out  
Ring  
Out  
Ring  
In  
Ring  
Out  
Ring  
In  
STH TCUs  
Figure 1-2. Improved Beacon Recovery Resolution for MAUs  
Page 1-6  
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Ge tting He lp  
1.4 Ge tting He lp  
If you need additional support related to the Cabletron Systems STH, or if  
you have any questions, comments, or suggestions concerning this  
manual, contact Cabletron Systems Technical Support:  
By phone:  
(603) 332-9400  
Monday-Friday; 8am - 8pm EST  
®
By CompuServe :  
GO CTRON from any ! prompt  
(603) 337-3075  
By Internet mail:  
By Fax:  
By BBS:  
(603) 337-3750  
By mail:  
Cabletron Systems, Inc.  
P.O. Box 5005  
Rochester, NH 03866-5005  
Page 1-7  
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CHAPTER 2  
REQUIREMENTS & SPECIFICATIONS  
This chapter describes network guidelines, power requirements, and  
operating specifications for the STH. Before installing the STH, read this  
chapter and confirm that the network meets the requirements and  
conditions specified in this chapter. Failure to follow these guidelines  
could result in poor network performance.  
2.1 Ge ne ra l Consid e ra tions  
All devices connected to the STH must meet IEEE 802.5 Token Ring  
specifications.  
Ma xim um Num b e r of Sta tions on a Ring  
The maximum stack composed of four 24-port STH hubs and one 24-port  
intelligent hub offers a total of 120 TCU ports, but the number of ports  
available on the LAN may be increased by the use of passive Multi-  
station Access Units (MAUs) (refer to Section 1.2.4, Su p p or t for  
P a ssive MAU Wor k gr ou p s). The recommended maximum number of  
stations in a single ring is 250 stations when using STP lobe cabling and  
150 stations when using UTP cabling anywhere on the ring.  
Crossta lk  
Crosstalk is interference caused by signal coupling between different  
cable pairs contained within a multi-pair cable bundle. Multi-pair cables  
should not be used for UTP lobe cabling. Avoid mixing Token Ring  
signals with other applications (voice, etc.) within the same cable.  
Noise  
Noise can be caused by either crosstalk or externally induced impulses.  
Outside systems (motors, switching equipment, fluorescent lighting, high  
amperage equipment) may produce electrical interference causing noise.  
The number and quality of cable connections also contribute considerably  
to noise levels. If noise induced errors are suspected, it may be necessary  
Page 2-1  
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Ge ne ra l Consid e ra tions  
to re-route cabling away from potential noise sources, or to ensure that  
the electrical wiring in the area is properly wired and grounded, or to  
replace connectors along affected segments.  
Te m p e ra ture  
The attenuation of PVC-insulated cable varies significantly with  
temperature. Check the cable manufacturer’s specifications. Plenum-  
rated cables are strongly recommended in areas where temperatures  
exceed 40˚C. Under such conditions, plenum-rated cables ensure that  
cable attenuation remains within specifications.  
Insta lla tion Re c om m e nd a tions  
In addition to complying with the cable specifications presented in  
Sections 2.2 and 2.3, the cabling installation should comply with the  
following recommendations to obtain optimum performance from the  
network:  
UTP cabling should be free of splices, stubs, or bridged taps.  
No more than two punch-down blocks should exist between TCU  
ports and wall outlets.  
Metal troughs, ducts, etc. carrying Token Ring signals should be  
properly grounded.  
Cables should be routed away from sources of electrical noise, such as  
power lines, fluorescent lights, electric motors, radio interference, and  
heavy machinery.  
Token Ring signals should not be routed through UTP cables that exit  
a building or which are adjacent to cables either exiting a building or  
exposed to lightning strikes and power surges.  
UTP cables that contain Token Ring signals should not be  
simultaneously used for applications which may impress high  
voltages (greater than 5 volts) with sharp rise or fall times, since the  
noise coupling from such signals could directly cause errors on the  
Token Ring network.  
For single telecommunications closet rings, lobe lengths should not  
exceed 100 meters of 22 to 24 AWG wire from the attaching device and  
the TCU port.  
Page 2-2  
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Ca b le Sp e c ific a tions  
Where practical, dedicated cable should be used for Token Ring  
signals.  
Work area wall plates and outlets used for the Token Ring network  
should be clearly labeled as Token Ring network lobe connections.  
2.2 Ca b le Sp e c ific a tions  
Take care in planning and preparing the cabling and connections for the  
network. The susceptibility of the LAN’s cables to crosstalk and noise  
determines the network’s error rate, and thus, the reliability of data  
propagation on the network. The quality of the connections, the length of  
cables and other conditions of the installation are critical factors in  
determining the reliability of the network.  
2.3 UTP Ca b ling Sp e c ific a tions  
Both UTP supporting modules (STH-22 / 24) support D-inside wiring  
(DIW) voice grade Unshielded Twisted Pair (UTP) cable as described  
below and in EIA SP-1907B. All category 5, all category 4, and some (see  
Section 2.3.2, UTP Lobe Len gth s, on page 5) category 3 UTP cables  
meet Token Ring network performance requirements.  
2.3.1 UTP Ca b le Ca te g orie s  
Both UTP concentrator modules (STH-22 / 24) support UTP cables  
classified as category 3, 4, and 5.  
UTP cable is categorized according to the following specifications:  
Page 2-3  
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UTP Ca b le Ca te g orie s  
Table 2-1. UTP Cable Category Specifications  
Signal  
Attenuation  
per 100m  
NEXT  
loss  
(@ 100m)  
UTP  
Cat.  
Operating  
Frequency  
Electrical  
Impedance  
4 MHz  
16 MHz  
4 MHz  
100±15%  
100±15%  
100±15%  
100±15%  
100±15%  
100±15%  
5.6 dB  
13.1 dB  
4.3 dB  
8.9 dB  
4.3 dB  
8.2 dB  
32 dB  
23 dB*  
47 dB  
38 dB  
63 dB  
44 dB  
3
4
5
16 MHz  
4 MHz  
16 MHz  
*below Token Ring performance requirement of 30.5 dB.  
Category 3 consists of (usually) four Unshielded Twisted Pairs of  
coincidentally the same as UTP Category 3.) It is typically used to wire  
cable runs within the walls of buildings. In some installations, pre-  
existing UTP building wiring can be used for Token Ring cabling.  
Wa r n in g: At 16 Mb/ s ring speeds, some Category 3 cable does not meet  
the performance requirements of a Token Ring network. This may  
impose lower limits on lobe cable distances and ring node counts. See  
Table 2-1.  
Categories 4 and 5 are higher quality versions of category 3. They use the  
same gauge of wire but demonstrate superior performance due to  
improvements in material quality and assembly (e.g. more twists per  
foot).  
Wa r n in g: Because Near-End Crosstalk (NEXT) contributes the  
majority of its detrimental effects near the end of a lobe cable, the  
quality of jumper cables and patch cables is most critical. Seek the  
highest practical grade. The quality of connectors and terminators is  
also critical.  
Wa r n in g: Telephone Battery and Ringing voltages used in UTP  
telephone circuits could present a shock hazard and can damage Token  
Ring equipment if connected to Token Ring cabling. DO NOT con n ect  
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UTP Lob e Le ng ths  
UTP ca blin g to a n y n on -Token Rin g n etwor k con d u ctor s  
(telephone, etc.) or gr ou n d . If in doubt, test wiring before using.  
2.3.2 UTP Lob e Le ng ths  
The physical length of the cable connecting a station to a TCU port on the  
concentrator is referred to as the lobe length. The maximum lobe length  
attainable with the concentrator, under ideal conditions, is shown in Table  
2-2. Cable routing, connector attenuation, noise, and crosstalk can  
adversely affect the maximum lobe length.  
Table 2-2. UTP Maximum Lobe Lengths.  
@ 4 Mb/s  
@ 16 Mb/s  
UTP  
Category  
meters  
(feet)  
meters  
(feet)  
3
4
5
200  
225  
250  
(656)  
(738)  
(820)  
100*  
110  
120  
(328)*  
(360)  
(393)  
* for cable with NEXT loss 30.5 dB per 100m  
Some UTP category 3 cables fail to meet the performance minimums  
required to support a Token Ring network. Whereas category 3 allows for  
near end crosstalk (NEXT) loss as low as 23 dB per 100 m at 16 Mb/s,  
Token Ring performance requirements demand a NEXT loss of at least  
30.5 dB. To safeguard against worst case conditions (running at 16 Mb/s  
and using category 3 cable with the category’s lowest qualifying NEXT  
loss—23 dB), the recommended maximum lobe length should be reduced  
to keep crosstalk interference within acceptable levels when using  
category 3 cable.  
2.4 STP Ca b ling Sp e c ific a tions  
Both STP concentrator modules (STH-42 / 44) support all STP cables  
classified as IBM Types 1, 2, 6, and 9. All cables meeting the criteria for  
classification as IBM Type 1, 2, 6, or 9 meet Token Ring network  
performance requirements.  
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STP Ca b le Ca te g orie s  
2.4.1 STP Ca b le Ca te g orie s  
The supported STP cable types meet the following specifications:  
Table 2-3. STP Cable Type Specifications.  
Attenuation per...  
IBM  
Type  
Operational  
Frequency  
Impedance  
1000 m  
(1000 ft)  
4 MHz  
16 MHz  
4 MHz  
150±15%  
150±15%  
150±15%  
150±15%  
22 dB  
45 dB  
33 dB  
66 dB  
(6.7 dB)  
(13.7 dB)  
(10.0 dB)  
(20.0 dB)  
1 & 2  
6 & 9  
16 MHz  
IBM Type 1 consists of two shielded twisted pairs (STP) of 22 AWG solid  
wire for data. Used for the longest cable runs within the walls of  
buildings.  
IBM Type 2 consists of six pairs of unshielded twisted pairs of 24 AWG  
solid wire and a shield casing. The two pairs carried within the shield  
casing are used to carry Token Ring data. The four pairs carried outside of  
the shield casing are typically used for voice communication. Type 2 is  
frequently used to wire cable runs within the walls of buildings.  
IBM Type 6 consists of two STP of 26 AWG stranded wire for data.  
Because of its high attenuation, Type 6 is used only in patch panels or to  
connect devices to/from wall jacks. Attenuation for Type 6 cable is 3/2 x  
Type 1 cable (attenuation for 66 m of Type 6 = attenuation for 100 m of  
Type 1).  
IBM Type 9 is similar to Type 1, but uses 26 AWG solid wire. Like Type 6,  
because of its high attenuation, Type 9 is used only in patch panels or to  
connect devices to/from wall jacks. Attenuation for Type 9 cable is 3/2 x  
Type 1 cable (66 m of Type 9 = 100 m of Type 1).  
2.4.2 STP Lob e Le ng ths  
The physical length of the cable connecting a station to a TCU port on the  
concentrator is referred to as the lobe length. The maximum lobe length  
attainable with the concentrator, under ideal conditions, is shown in Table  
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TCU Sp e c ific a tions  
2-4. Cable routing, connector attenuation, noise and crosstalk can  
adversely affect the maximum lobe length.  
Table 2-4. STP Maximum Lobe Lengths.  
@ 4 Mb/s  
@ 16 Mb/s  
STP  
Types  
meters  
(feet)  
meters  
(feet)  
1 & 2  
6 & 9  
300  
200  
(984)  
(656)  
150  
100  
(492)  
(328)  
Mixe d STP C a b le Typ e s  
If cable types are to be mixed in the LAN, compensations must be made  
for the different cable attenuations. For example, Type 6 & 9 cables can be  
run for only 2/3 the distance of Type 1: 100 meters of Type 1 66 meters  
of Types 6 or 9)  
2.5 TCU Sp e c ific a tions  
All STH models provide RJ45 TCU connectors for network connections.  
The STH-22/-24 supports UTP and the STH-42/-44 supports STP. Each  
TCU port is internally crossed-over to provide connections for straight-  
through station lobe cabling.  
Cable Shield*  
TX+  
8
7
RX-  
RX+  
TX-  
6
5
4
3
2
1
*Cable Shield  
not used  
MALE  
RJ45  
with UTP cabling  
Cable Shield*  
Figure 2-1. TCU pinouts  
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Op e ra ting Sp e c ific a tions  
On STH models -42/-44, each RJ45 connector is encased in a metallic  
shield which provides a means of connection for the STP cable shield.  
Shield continuity is maintained by contacts within the female RJ45 that  
contact the metallic casing of the male RJ45 on the STP lobe cabling.  
Shielded patch cables that adapt a shielded RJ45 to a Media Interface  
Connector (MIC) are available from Cabletron Systems in eight-foot  
lengths. These adapter/patch cables permit connection to an existing  
patch panel equipped with MICs.  
2.6 Op e ra ting Sp e c ific a tions  
Cabletron Systems reserves the right to change these specifications at any  
time without notice.  
2.6.1 Ring Sp e e d  
The operating ring speed for the STH hub may be set via the Ring Speed  
Switch on the front face of the STH or by MIB commands from an  
intelligent hub.  
If the STH hub has had no connection to any intelligent hub since power-  
up, the Ring Speed switch effects immediate changes in the hub’s ring  
speed. Under normal conditions, however (when the STH is being  
managed by an intelligent hub), the STH hub’s Ring Speed switch setting  
is read only at power-up. In order to change the STH hub’s ring speed via  
the Ring Speed switch, the user must change the switch setting and  
power-cycle the STH (unplug its power cord and plug it in again).  
MIB commands from intelligent hubs override the Ring Speed switch  
setting. Once the switch setting has been overridden, the MIB command  
ring speed setting will remain in effect at all subsequent power-ups as  
long as the switch setting on the STH is not changed. MIB commands are  
accessible through the MIB Navigator screen on the intelligent hub’s  
Local Management application and through other SNMP network  
management software packages including Cabletron Systems’ Remote  
®
LANVIEW / Windows.  
The user may cancel the MIB override and regain switch control over the  
STH hub’s ring speed by changing the current switch position and  
power-cycling the STH.  
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Ring Se q ue nc e  
Note: When cancelling a MIB override, the user may have to perform  
the switch and power-cycle procedure twice (as described in the steps  
below) to actually ch a n ge the STH hubs ring speed by the switch.  
To return to switch control from an MIB overridden Ring Speed setting:  
1. Regain switch control. Change the current switch setting and power-  
cycle the STH. Regardless of the final desired speed, the user must  
toggle the switch opposite its current position and then power-cycle  
the STH to put a switch-position change into effect, cancelling the  
MIB override.  
2. Select the desired ring speed. If the Ring Speed switch setting is not  
yet the desired setting (it may be the same as the former setting from  
the MIB command), the user must again change the switch setting  
and power-cycle the STH to complete the change from the MIB-  
commanded speed setting to the desired switch-set speed setting,  
2.6.2 Ring Se q ue nc e  
When STH hubs are stacked, they are interconnected via the intelligent  
hub to create a larger ring network. The ring sequence for the stations on  
the ring (the order in which stations are logically arranged on the ring) is  
determined by the physical location of each TCU connection in the stack.  
It progresses in ascending stack number and port number order. The  
sequence is changed each time a station is inserted or de-inserted from a  
ring.  
To determine the ring sequence, consider only those ports inserted into  
the ring. Begin with the STH numbered lowest in the stack and list (in  
ascending numerical order) the number of each inserted port. Repeatedly  
move to the next STH and list the inserted ports in numerical order until  
all ports inserted into the ring have been listed. The order is continuous,  
wrapping directly from the stack’s last inserted port to the first—from the  
bottom of the list, right back to the top.  
2.6.3 Powe r Sup p ly Re q uire m e nts  
Note: The STH has a universal power supply which will accept input  
power from 90 to 264 VAC, 47-63 Hz.  
The power supply has two outputs of +5 volts and +12 volts. The  
maximum output power is 20 watts and the minimum efficiency is 65%  
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Environm e nta l Re q uire m e nts  
under all conditions of line at full load. The minimum and maximum  
load current from each output is shown below.  
Table 2-5. Power Supply Loads  
Output  
Min. Load  
Max. Load  
Max Power  
+5 Volts  
0.50 Amps  
0.05 Amps  
3.0 Amps  
1.0 Amps  
15 Watts  
12 Watts  
+12 Volts  
2.6.4 Environm e nta l Re q uire m e nts  
Operating Temperature:  
Non-operating Temperature:  
Operating Humidity:  
+5° to +50° C  
-30° to +90° C  
5 to 95% (non-condensing)  
2.6.5 Sa fe ty  
This equipment is designed in accordance with UL478, UL910, NEC 725-  
2(b), CSA, IEC, TUV, VDE Class A, and meets FCC Part 15, Class A limits.  
Wa r n in g: It is the responsibility of the person who sells the system to  
which the STH will be a part to ensure that the total system meets  
allowed limits of conducted and radiated emissions.  
2.6.6 Physic a l  
Dimensions:  
2.8H x 17.0W x 8.0D inches  
(7.2 x 43.6 x 20.5 cm)  
Predicted MTBF:  
(mean time between failure)  
STH-22/42: 653,987 hours  
STH-24/44: 653,972 hours  
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CHAPTER 3  
INSTALLATION  
This chapter outlines the procedure for installing the STH and adding it  
to a stack. Confirm that the network meets the guidelines and  
requirements outlined in Chapter 2, Installation Requirements/  
Specifications, before installing the STH.  
3.1 Unp a c king the STH  
Unpack the STH as follows:  
1. Carefully remove the STH from the shipping box. Preserve the  
shipping box and packing materials for future use.  
2. Visually inspect the STH. If there are any signs of damage, contact  
Cabletron Systems Technical Support immediately.  
3.2 Insta lling the STH  
All installations must meet the requirements listed below:  
A single phase 120Vac, 15A, grounded power receptacle must be  
within 7 feet of the STH.  
Shelving units must be able to support 30 pounds of static weight per  
hub in the stack.  
The temperature for the selected location must be maintained  
between 5° and 50°C, and fluctuate less than 10°C per hour.  
The following sections provide instructions for stacking the STH.  
3.2.1 Ra c k Mount or Wa ll Mount Ha rd wa re  
Provided with the STH is an accessory kit that includes Rack Mount  
Brackets for installations into 19 inch racks, Wall Mount Brackets and  
Mounting Screws for installations on walls, and a Strain Relief Bracket to  
minimize stresses imflicted by cables hanging from the TCU ports.  
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Ad d ing the STH to a Sta c k  
3.2.2 Ad d ing the STH to a Sta c k  
STH hubs are star-wired to the intelligent hub. To add STH hubs to a  
stack, refer to Figure 3-1 and perform the following steps:  
1. Attach an STH HubSTACK Interconnect cable to the "STACK" port on  
the rear panel of an STH.  
2. Attach the other end of the cable to one of the numbered STACK ports  
on the back panel of the intelligent hub.  
The port’s number determines the relative position of the STH hub in  
the network’s ring sequence and is used by the intelligent hub’s  
management system to identify the STH to the user.  
3. Repeat steps 1 and 2 to attach up to four STH hubs in the stack.  
®
TOKEN RING HUB with LANVIEW  
STH-24  
SN  
RESERVED  
STACK  
®
TOKEN RING HUB with LANVIEW  
STH-24  
STH-24  
STH-24  
SN  
RESERVED  
STACK  
®
TOKEN RING HUB with LANVIEW  
SN  
RESERVED  
STACK  
®
TOKEN RING HUB with LANVIEW  
SN  
RESERVED  
STACK  
MicroMMAC-24TTOKEN RING HUBWITH LANVIEW®  
STACK 1  
STACK 2  
STACK 3  
STACK 4  
Figure 3-1. Stacking the STH  
To disconnect an STH hub from the stack, simply unplug its HubSTACK  
Interconnect cable from the intelligent hub.  
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Atta c hing the Stra in Re lie f Bra c ke t  
3.2.3 Atta c hing the Stra in Re lie f Bra c ke t  
Attach the strain relief bracket to the front of the STH as follows:  
1. Locate the strain relief bracket and four 8-32 x 3/8" screws from the  
Wa r n in g: Use of longer screws may cause damage to the unit or  
electrical shock.  
2. Carefully turn the STH upside down.  
3. Attach the strain relief bracket to the bottom of the STH as shown in  
Figure 3-2.  
1 X 1 0 1 X 2 X 9 1 X  
1 X  
8 X  
7 X  
6 X  
5 X  
4 X  
3 X  
2 X  
S P E E D  
4 M  
A C  
S
K
T
1 6 M b / s  
P W R  
1 6 M  
1 8 X 1 7 X 1 6 X 1 5 X 1 4 X 1 3 X  
2 4 X 2 3 X 2 2 X 2 1 X 2 0 X 1 9 X  
S T H - 2 4  
A C K T P H u b S T  
O K  
S U E P P N O R R T I I N N G G 1 0 H 0 O U H B M U w i t h L A N V I E W  
C A B L E  
T
®
Figure 3-2. Attaching the Strain Relief  
3.2.4 Ra c k-Mounting the STH  
Perform these steps to install the STH in a 19-inch rack:  
front edges of each side of the STH.  
2. Using the four cover screws removed in step 1, attach the rack  
mounting brackets to each side of the STH as shown in Figure 3-3.  
3. With the mounting brackets installed, position the STH between the  
vertical frame members of the 19-inch rack and fasten it securely with  
the mounting screws as shown in Figure 3-4.  
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Wa ll-Mounting the STH  
Ra c k Mo unting Bra c ke ts (2)  
TOKEN RING HUB with LANVIEW®  
HubSTACK  
STH-24  
SUPPORTING 100 OHM UTP CABLE  
24X 23X 22X 21X 20X 19X  
18X 17X 16X 15X 14X 13X  
PWR  
16Mb/s  
STACK  
4M  
16M  
SPEED  
6X  
5X  
4X  
3X  
2X  
1X  
12X 11X 10X  
9X  
8X  
7X  
Sc re ws (4)  
Figure 3-3. Installing the Rack-Mount Brackets  
19-Inc h Ra c k  
®
TOKEN RING HUB with LANVIEW  
HubSTACK  
STH-24  
SUPPORTING 100 OHM UTP CABLE  
24X 23X 22X 21X 20X 19X  
18X 17X 16X 15X 14X 13X  
PWR  
16Mb/s  
STACK  
4M  
16M  
SPEED  
6X  
5X  
4X  
3X  
2X  
1X  
12X 11X 10X  
9X  
8X  
7X  
Sc re ws (4)  
Figure 3-4. Installing the STH in a Rack  
3.2.5 Wa ll-Mounting the STH  
When an STH is installed on a wall, its cable connections must face down  
to prevent the sideways stresses of hanging cables from compromising  
the connection at the port.  
Note: 1/ 4-inch anchors for wall mounting are not included with the  
STH-ACCY-KIT package.  
1. Use the supplied screws to attach the wall mounting brackets to the  
bottom of the STH as shown in Figure 3-5. There are two brackets, one  
for each side.  
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Wa ll-Mounting the STH  
Figure 3-5. Installing the Wall Mounting Brackets  
2. Select the wall location for the STH within 7 feet of a power outlet.  
Wa r n in g: There is a SHOCK HAZARD whe drilling into walls  
containing electrical wiring. Select a wall location where drill bits and  
screw anchors will not come in contact with electrical wiring in the wall.  
3. Get a pencil. With the wall mounting brackets attached to the STH,  
position the STH against the wall where it will be permanently  
mounted with the network port facing down, as shown in Figure 3-6,  
and mark the screw holes’ positions on the wall.  
4. Set the STH aside and carefully drill four 1/4" pilot holes, one for each  
screw anchor.  
5. Install the screw anchors.  
6. Position the STH on the wall, aligning the screw holes over the  
anchors and reinstall the four anchor screws to attach the STH to the  
wall. Tighten the four anchor screws.  
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Fre e -Sta nd ing Insta lla tion  
Solid Wall Anchor  
Wall Mounting Bracket  
attached to STH  
Mounting Screws  
Pre-Drilled Holes  
with Anchors  
Hollow Wall Anchor  
Figure 3-6. Wall-mounting the STH  
3.2.6 Fre e -Sta nd ing Insta lla tion  
For a free-standing shelf or tabletop installation, install the STH on an  
unrestricted free surface area 21 inches wide, 18 inches deep and 6 inches  
high, within 7 feet of its power source, as shown in Figure 3-7.  
21 IN.  
18 IN.  
TOKEN RING HUB with LANVIEW®  
HubSTACK  
STH-24  
SUPPORTING 100 OHM UTP CABLE  
24X 23X 22X 21X 20X 19X  
18X 17X 16X 15X 14X 13X  
PWR  
6 IN.  
16Mb/s  
STACK  
4M  
16M  
SPEED  
12X 11X 10X  
9X  
8X  
7X  
6X  
5X  
4X  
3X  
2X  
1X  
7 FT.  
Figure 3-7. Shelf or Table-top Installation  
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Conne c ting the STH to the Powe r Sourc e  
3.2.7 Conne c ting the STH to the Powe r Sourc e  
Note: The STH has a universal power supply which will accept power  
sources from 90 Vac to 264 Vac, 47-63 Hz.  
To connect the STH to the power source:  
1. Plug the power cord into the back panel of the STH.  
2. Plug the other end of the power cord into a grounded wall outlet.  
3. Verify that the PWR LED is on, this indicates that the STH is receiving  
power.  
3.2.8 Atta c hing Ne twork Ca b ling to TCU Ports  
Twisted pair segments are connected to the RJ45 TCU Ports on the front  
panel of the STH. To connect twisted pair segments to the STH:  
1. Insert the RJ45 connector from each twisted pair segment into the  
desired network port on the STH. See Figure 3-8.  
13X  
14X  
15X  
16X  
17X  
18X  
1X  
2X  
3X  
4X  
5X  
6X  
Figure 3-8. TCU Port Connections  
2. Confirm that the port’s corresponding LNK LED is on. If the LED is  
not on, perform each of the following steps:  
a. Check that the Token Ring device at the other end of the twisted  
pair segment is powered up.  
b. Verify that the RJ45 connector on the twisted pair segment has the  
proper pinouts. Check the cable for continuity.  
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Finishing the Insta lla tion  
c. Check that the twisted pair connection meets dB loss and cable  
specifications outlined Chapter 2.  
If a link still has not been established, contact Cabletron Systems  
Technical Support.  
3.3 Finishing the Insta lla tion  
The STH is now ready for operation. Before placing the network into  
service, test the installation thoroughly, making sure that all stations are  
addressable and that the STH and all stations are indicating normal  
operation. Confirm that all networking software is configured properly to  
match the installed network. If abnormal operation conditions emerge,  
proceed to Chapter 4, TROUBLESHOOTING.  
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CHAPTER 4  
TROUBLESHOOTING  
This chapter contains instructions for using LANVIEW LEDs to  
troubleshoot physical layer network problems.  
4.1 LANVIEW LED Sig na ls  
The STH incorporates the Cabletron Systems LANVIEW Status  
Monitoring and Diagnostics System. LANVIEW LEDs can help diagnose  
problems such as a power failure or a cable fault. The STH includes the  
following LANVIEW LEDs:  
Table 4-1. LED Signals  
LED  
Color  
Condition  
Green  
off  
Power on.  
Power off.  
PWR  
Yellow  
off  
Ring Speed set to 16 Mbps.  
16 Mb  
Ring Speed set to 4 Mbps.  
Green  
Red  
off  
Connection with intelligent hub intact.  
Bypassed or disconnected from intelligent hub.  
Port enabled but not linked.  
STACK  
Green  
Red  
Port enabled and linked.  
Ports  
Port disabled (or set to Ring Out) and not linked.  
Blinking  
Red  
Ring Speed Fault -OR- Port linked but disabled.  
4.2 Troub le Re solution  
If this section does not guide the user to a solution, please contact  
Cabletron Systems Technical Support (see Section 1.4, Gettin g Help .)  
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Troub le Re solution  
Loss Of Powe r  
If the STH is having power problems, check the power delivery system  
(power cable, power outlet, circuit breaker, fuse).  
Loss of Conta c t with Inte llig e nt Hub  
If the STACK LED is indicating disconnection from the intelligent hub, it  
may be that the intelligent hub has placed the STH in bypass to protect  
itself from beaconing conditions or a mismatched ring speed on the STH.  
Check the STH for beaconing conditions and make sure that the STH is  
operating at the same rings speed as the intelligent hub.  
It may be that the STH is physically disconnected from the intelligent hub  
by a disconnected or faulty cable. Check the hardware.  
Fa ilure to Link on Ena b le d Port  
Check that the Token Ring devices at either end of the cable are powered-  
up.  
Verify that the network cable’s connectors have the proper pinouts. Refer  
to Section 2.5, TCU Sp ecifica tion s.  
Check the cable for continuity. A variety of tools are available for this test,  
depending on the media you are using.  
Check that the cables specifications for dB loss described in Chapter 2.  
Ring Sp e e d Fa ult  
The network device being linked at this port is operating at a ring speed  
different from the STH’s currently set ring speed. Set the two devices to  
the same speed.  
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