Manuale d’uso / di manutenzione del prodotto bridges del fabbricante Cabletron Systems
Vai alla pagina of 132
Cabletron Systems Networking Guide Workgroup Solutions.
.
i Notice Notice Cabletron Systems r eserves the right to make changes in specifications and other information contained in this document without prior notice. The reader should in all cases consult Cabletr on Systems to determine whether any such changes have been made.
Notice ii.
iii Chapter 1 Intr oduction Using This Guide ......................................................................................................................... 1-1 Document Organization ..........................................................
Contents iv Chapter 5 Netw ork Design The Role of the W orkgroup ........................................................................................................ 5-2 W orkgroup Establishment Criteria ...........................................
v Contents Appendix A Char ts and T ables W orkgroup Design T ables ......................................................................................................... A-1 Ethernet ................................................................
Contents vi.
1-1 Chapter 1 Intr oduction Using This Guide The Cabletron Systems Networking Guide - W orkgroup Solutions is intended to provide much of the information necessary to allow Network Managers to design and evaluate workgroup networks using the Cabletr on Systems family of standalone and stackable networking products.
Introduction 1-2 Document Organization Document Or ganization The following summarizes the organization of this manual: Chapter 1, Introduction , provides basic information about this document, including the organization and format of the document.
Document Conv entions 1-3 Introduction Document Con ventions W arnings and Notifications Formats References to chapters or sections within this document ar e printed in boldface type. References to other Cabletr on Systems publications or documents are printed in italic type.
Introduction 1-4 Related Documentation Related Documentation The following publications may be of assistance to you in the design process. Several of these documents present information supplied in this guide in gr eater or lesser detail than they are pr esented here.
2-1 Chapter 2 Re vie w of Netw orking This chapter discusses the defining characteristics of three major Local Area Network (LAN) technologies. Before discussing the selection of networking har dware for workgr oup design, an understanding of the major standardized networking technologies available for these designs is necessary .
Re view of Netw or king 2-2 Ether net Ethernet Ethernet is a local area networking technology that was initially developed in the 1970s by the Xerox Corporation. It is based on the principles of workstations being responsible for their own transmissions and operation.
F ast Ether net 2-3 Re view of Netw or king • AUI Length: The maximum Attachment Unit Interface (AUI) cable length is 50 m for connections from a transceiver to an Ethernet device. The 50 m distance is the allowable maximum for standard AUI, while a maximum length of 16.
Re view of Netw or king 2-4 F ast Ether net This signal path, two end stations and the repeaters between them, is called the network radius. Unlike standard Ethernet networks, Fast Ethernet networks have a maximum network radius that may restrict the lengths of station cabling to less than the maximum allowable distances for single links.
T oken Ring 2-5 Re view of Netw or king Fast Ethernet networks designed using Class II repeaters may not exceed the following maximum network radii: - 200 m for homogenous 100BASE-TX networks - 320 m .
Re view of Netw or king 2-6 T oken Ring The transmission and reception of the token determines the amount of time that any station will have to transmit data during its turn, offering a measur e of predictability not available in Ethernet or Fast Ethernet.
T oken Ring 2-7 Re view of Netw or king T oken Ring networks can use a variety of physical cabling, including Unshielded T wisted Pair (UTP), Shielded T wisted Pair (STP), or fiber optic cabling. The characteristics of the various cables can directly impact the operational limitations of a T oken Ring network which uses a particular media.
Re view of Netw or king 2-8 T oken Ring • Number of Stations Per 4 Mbps T oken Ring: In the same fashion as the limits imposed on cable lengths due to the operating speed of the network and type of cabling used, there ar e limitations on the number of stations that may be connected to a single ring using active circuitry .
T oken Ring 2-9 Re view of Netw or king There ar e other limitations involved in the IEEE 802.5 standard and the various cable specifications that are mor e detailed and complex. These limitations are covered in detail in the Cabletr on Systems Cabling Guide and the Cabletr on Systems T oken Ring T echnology Overview .
Re view of Netw or king 2-10 T oken Ring.
3-1 Chapter 3 The W orkgr oup Appr oac h This chapter describes the basic operation and design of stackab le and standalone de vices and the methods used to meet common networking needs with these de vices. Standalone and stackable networking devices are specialized and important parts of any end-to-end network design strategy .
The W or kgroup Approach 3-2 Standalones Standalones, the Original Networking De vices Standalone devices are the second oldest devices in Local Area Networking, having been developed shortly after transceivers.
Standalones 3-3 The W or kgroup Approach Management of Standalones As standalone devices became more complex, the need to contr ol them became greater . The need to have some form of troubleshooting and contr ol process in place for an eight-port repeater is minimal.
The W or kgroup Approach 3-4 Stackab les Stac kables T o cope with the limited flexibility and expandability of standalones, the stackable hub, or stackable, was developed. The stackable design allowed a series of devices to act as a single device. W ith a stackable hub system, five separate devices could act as a single device.
Stackab les 3-5 The W or kgroup Approach How Stac ks W ork Stackable hubs communicate with one another through pr oprietary interconnection cables. The cables used in Cabletr on Systems’ stackable hub solution are called HubST ACK Interconnect Cables.
The W or kgroup Approach 3-6 Stackab les HubST ACK Interconnect Cables are connected in a particular sequence, fr om the OUT port of the first device in the stack to the IN port of the next. This arrangement is repeated fr om device to device as more stackable hubs ar e incorporated in the stack, as shown in Figure 3-3.
Stackab les 3-7 The W or kgroup Approach Initially , Network Designers wishing to make connections from stacks to backbone technologies would be forced to add an additional standalone device to the network at the workgroup ar ea.
The W or kgroup Approach 3-8 Stackab les In addition, stackable and standalone devices are typically available for only the most common of networking media: UTP and STP .
4-1 Chapter 4 PIMs and BRIMs This chapter deals with the special methods of connecting standalone and stackab le de vices to one another regardless of cabling media or netw orking technology .
PIMs and BRIMs 4-2 P or t Interface Modules The PIMs can be added at any time, allowing a Network Manager to add capabilities for special links at any time.
P or t Interface Modules 4-3 PIMs and BRIMs The suffix of the PIM’s pr oduct name, which follows the hyphen, specifies what media type and connector style the PIM provides. T ypically any alphabetic characters indicate the media, while numerical characters indicate a special connector type for that media.
PIMs and BRIMs 4-4 P or t Interface Modules TPIMs TPIMs are T oken Ring Port Interface Modules. A TPIM provides a single T oken Ring connection. If the T oken Ring device the TPIM has been placed in allows it, the TPIM connection can be used as either a station port or a RI/RO port.
P or t Interface Modules 4-5 PIMs and BRIMs APIMs The Asynchronous T ransfer Mode (A TM) Port Interface Modules, or APIMs, ar e designed to allow connection to differing A TM networks, supporting not only differ ent media, but differ ent speeds of A TM transmission.
PIMs and BRIMs 4-6 P or t Interface Modules T able 4-1 provides basic information r egarding the available PIMs and the connectors, media, and technologies they support.
P or t Interface Modules 4-7 PIMs and BRIMs FPIM-00 FDDI Multimode Fiber Optics FDDI MIC FPIM-01 FDDI Multimode Fiber Optics SC FPIM-02 FDDI UTP RJ45 FPIM-04 FDDI STP RJ45 FPIM-05 FDDI Single Mode Fib.
PIMs and BRIMs 4-8 Bridge/Router Interface Modules Bridge/Router Interface Modules In the same way that Cabletron Systems supplied a method for connecting a single network technology to differ ent typ.
Bridge/Router Interface Modules 4-9 PIMs and BRIMs BRIM-F6 The BRIM-F6 is an FDDI bridging device used to connect a standalone device to an FDDI network. The BRIM-F6 provides two user -configurable FPIM slots, allowing the Network Designer to specify and use any type of standard FDDI media for connection to the BRIM.
PIMs and BRIMs 4-10 Bridge/Router Interface Modules The available BRIMs and the technologies they support are detailed in T able 4-2. This table can be useful for the selection of a BRIM when designing a workgroup requiring a connection to a particular networking technology .
5-1 Chapter 5 Netw ork Design The f ollo wing chapter discusses some of the more common approaches to workgroup network design. The network design process is the formation of the network fr om initial concept to the plan of implementation.
Network Design 5-2 The Role of the W orkgroup As this Networking Guide is concerned with the decisions made regar ding networking hardwar e and not with the administration of networks or the specific.
The Role of the W orkgroup 5-3 Network Design W orkgroup Estab lishment Criteria This section examines some of the methods that may be used to divide the population mass of end users of a network into cohesive and defined workgroups.
Network Design 5-4 The Role of the W orkgroup Departmental Organization Corporations, companies, and agencies all separate employees by primary function. No one person “does it all,” and most employees are specialists in the sense that they perform one function or a series of functions that are assigned to them by their job descriptions.
The Role of the W orkgroup 5-5 Network Design As the creation of workgr oups based on departmental organization mirr ors the operation of the company , the expandability of the network is simplified;.
Network Design 5-6 The Role of the W orkgroup Common Function Segmentation by common function is often used to provide further division of the network within larger overall departments, or to facilitate the use of certain network applications by specific end users common throughout much of the department.
The Role of the W orkgroup 5-7 Network Design Priority Organization Priority organization is a flexible term that r efers to the Network Manager assigning devices to workgroups based on specific priorities.
Network Design 5-8 The Role of the W orkgroup Priority organization of this manner in a single-segment network involves providing stations in the priority workgr oups with qualities of media and network connection based on that priority .
The Role of the W orkgroup 5-9 Network Design Selecting W orkgroup T echnologies The selection of a network technology at the workgroup level is a very important decision, and one that should be made only after careful consideration and evaluation.
Network Design 5-10 Creating a Manageable Plan Creating a Manageable Plan A well thought-out and carefully designed network is still difficult to troubleshoot if no one else knows how it is or ganized.
Creating a Manageable Plan 5-11 Network Design • Centralization and Control - If you r equire mor e control over the networking hardwar e than you can get from locking it away , you can place many devices in one central location such as a Network Management office.
Network Design 5-12 Creating a Manageable Plan Use a standard, decipherable labeling code for cable and har dware. A label reading L2N5W2C1S243 may look like gibberish now , but if you know that the letter codes indicate locations or conditions of installation, it can be quite helpful.
Creating a Manageable Plan 5-13 Network Design Single P oints of Failure A single point of failure is any one device, cable or connection that, if it should fail or be removed fr om the network, would disable all or a sizable part of the network.
Network Design 5-14 Creating a Manageable Plan Isolation and Recovery No matter how much redundancy is designed into a network, and no matter how much the single points of failure ar e eliminated, the law of averages eventually catches up to any network, and a failure will occur .
Network Expandability 5-15 Network Design T racking Changes Y our network maps will be used for keeping track of a large amount of information, which will naturally change over time.
Network Design 5-16 The W orkgroup as the Network The W orkgr oup as the Netw ork In many cases, the only network that a facility requir es is a single workgroup. Depending on the bandwidth, segmentation, and security requir ements of any facility , the single workgroup may be all that is needed.
The W orkgroup in the Larger Network 5-17 Network Design What Is a Bac kbone? A backbone is a network segment or cable which is used to provide for the interconnection of a number of smaller workgr oups or self-contained networks. The outlying networks, workgroups, or hubs communicate with one another through the backbone network.
Network Design 5-18 The Workgroup in the Larger Network The Distributed Bac kbone One method of creating a backbone network is to sequentially string all of the workgroup networks or hubs together . Cabling is run from one workgr oup hub to the next, providing the necessary connections.
The W orkgroup in the Larger Network 5-19 Network Design The Collapsed Backbone It is also possible to run cables fr om a central point, often a network management office or central wiring closet, out to each workgr oup network and back. These cabling runs ar e then terminated at a central point such as a patch panel.
Network Design 5-20 The Workgroup in the Larger Network • Simplified T roubleshooting - W orkgroups can be bypassed by simply reconfiguring a single patch panel. This can easily isolate a pr oblem segment for troubleshooting, and keeps the backbone network fr om being kept in a fault condition.
The W orkgroup in the Larger Network 5-21 Network Design • Simplified T roubleshooting - The device collapsed backbone, by connecting the workgroups thr ough a manageable device, provides not only simplified troubleshooting, but the ability to detect some backbone faults befor e they become network failures.
Network Design 5-22 The Workgroup in the Larger Network.
6-1 Chapter 6 Ethernet This chapter describes in detail the processes and decisions inv olved in designing an Ethernet workgroup using Cab letron Systems products.
Ether net 6-2 Ether net W orkgroup Devices Ethernet W orkgroup Devices The following sections describe the various Cabletron Systems networking devices that may be used in an Ethernet workgroup implementation. These Ethernet devices are divided into two categories - shar ed Ethernet devices and switched Ethernet devices.
Ether net W orkgroup Devices 6-3 Ether net T ype The type column describes what functions the device in question performs. There are thr ee basic types of devices covered by this table. Repeaters ar e standalone Ethernet multiport repeaters. They count as a single r epeater hop for purposes of calculating maximum network size or propagation delay .
Ether net 6-4 Ether net W orkgroup Devices Switched De vices Ethernet segmentation and switching designs requir e some slightly differ ent information and decisions.
Ether net W orkgroup Design 6-5 Ether net Ethernet W orkgroup Design When designing a new workgroup, one of the first tasks to be confr onted is the selection of a technology and an approach to the network.
Ether net 6-6 Ethernet Workgroup Design Abstracting the Design Process There ar e a series of logical stages that must be kept in mind when designing a network for any location, including the relatively simple home of fice.
Ether net W orkgroup Design 6-7 Ether net Some Cabletron networking devices, thr ough their support of PIMs and BRIMs, will support a small number of connections using differ ent media. For example, an Ethernet network which is made up primarily of 10BASE-T links has a single multimode fiber optic connection to a distant building.
Ether net 6-8 Ethernet Workgroup Design In an effort to pr ovide some measure of dif ferentiation between the varying levels of expense, the design tables which list a series of possible selections in a particular category attempt to organize the networking devices pr esented in ascending order of expense.
Ether net W orkgroup Design 6-9 Ether net The table below shows the selection field of Cabletron Systems shar ed Ethernet workgroup devices. This is the same table that was displayed at the beginning of this chapter .
Ether net 6-10 Ether net W orkgroup Design The media selected for the network is inexpensive Category 3 UTP jumper cabling. The low cost, durability , and ready availability of UTP makes it by far the preferr ed media for this installation.
Ether net W orkgroup Design 6-11 Ether net The Network Designer checks the Cabletron Systems Networking Solutions Pr oduct Guide to examine the characteristics and full description of the MR9T .
Ether net 6-12 Ether net W orkgroup Design The small office location is an ideal place to examine the suitability of stackable networking devices. As these locations fall into a space between tiny workgroups and full-scale facility networks, they are the tar get location for stackables.
Ether net W orkgroup Design 6-13 Ether net Expandability The simplicity and fluidity of expansion in a small office setting is of paramount importance. Every small office wants to expand, even if it is an addition of nothing more than a few additional networked computers.
Ether net 6-14 Ether net W orkgroup Design Design Example The following example follows a Network Designer ’s selection process for a small office Ethernet network. As in the previous example, the Network Designer has already decided upon a networking technology (Ethernet) and a media type (10BASE-T) for the network.
Ether net W orkgroup Design 6-15 Ether net As the network will be using UTP cabling, the SEHI-22FL can be removed from the selection field. Since growth is expected to be minimal, the Network Designer turns to examine the products that can be used in standalone mode.
Ether net 6-16 Ether net W orkgroup Design through an inter connect cable and have a stack providing 36 ports. This entir e stack will act as a single repeater , and the management functions that are included in the SEHI-24 will be applied also to the SEH-22 in the stack.
Ether net W orkgroup Design 6-17 Ether net Figure 6-5. FDDI Backbone Internetworking The main differ ence between the small office and the r emote office is that a provision must be made to accommodate a connection to a dif ferent networking technology .
Ether net 6-18 Ether net W orkgroup Design Design Example For an example of remote of fice workgroup configuration, we will build upon the previous small of fice example. Let us assume that there has been no gr owth of the small office network, but the pottery distributor has been pur chased by a larger , nationwide chain of distributors.
Ether net W orkgroup Design 6-19 Ether net Figure 6-6. Ethernet Remote Office Implementation The High-End Depar tment The high-end department is a workgroup with specialized needs, demanding high reliability or high thr oughput to each and every station.
Ether net 6-20 Ether net W orkgroup Design Management In a network using any form of segmentation, whether it is bridging, switching, or routing, management functionality is a part of the devices needed to cr eate the network. W ithout some form of management, segmentation decisions can not be made by the devices.
Ether net W orkgroup Design 6-21 Ether net Design Example As an example, we can examine a network design that is being planned for a group of Computer -Aided Design (CAD) engineers in a large ar chitectural firm.
Ether net 6-22 Ether net W orkgroup Design The Network Designer is looking for one or more per -port Ethernet switches that can be used to make network connections to the stations in the CAD department. The Network Designer examines the selection field of Ethernet switches, shown in T able 6-2.
Ether net W orkgroup Design 6-23 Ether net The Network Designer selects the ESX-1320 and calculates that two ESX-1320 switches, each containing one BRIM module for an FDDI connection, will meet the needs of the CAD department. The Network Designer would then go on to select the correct BRIMs and any necessary PIMs for these switches.
Ether net 6-24 Ether net W orkgroup Design P erm utations It is also possible to use an Ethernet switch to connect a series of individual workgroups, rather than workstations or other devices. In these situations, the Ethernet switch acts as a device collapsed backbone for the network.
7-1 Chapter 7 F ast Ethernet This chapter e xamines the decisions and selections that must be made when designing a F ast Ether net workgroup solution.
F ast Ether net 7-2 F ast Ether net W orkgroup Devices The columns in the table provide the same information that T able 6-1 provides regar ding Ethernet devices. Switched De vices Cabletron Systems pr oduces one Fast Ethernet switching device, the FN100.
F ast Ether net W orkgroup Design 7-3 F ast Ether net F ast Ethernet W orkgr oup Design The network design process for Fast Ethernet workgr oups is nearly identical to that used for standard Ethernet workgr oups.
F ast Ether net 7-4 F ast Ether net Workgroup Design P ort Count The first device in the stack, whether an intelligent SEHI100TX-22 or non-intelligent SEH100TX-22, will provide connections for up to 22 Fast Ethernet stations.
F ast Ether net W orkgroup Design 7-5 F ast Ether net The current network consists of 43 stations, including the shar ed servers and order entry system. The department curr ently operates on two standalone 24-port Ethernet repeaters that ar e connected to one another with a single jumper cable.
F ast Ether net 7-6 F ast Ether net Workgroup Design This expansion can continue until the stack contains five devices, the maximum number allowable with the stackable hub design. At this limitation, the stack will be capable of supporting up to 1 10 Fast Ethernet users.
F ast Ether net W orkgroup Design 7-7 F ast Ether net Abstracting the Design Process As the Fast Ethernet switch selection field, shown in T able 7-2, contains only one device, the amount of decision-making remaining in the design pr ocess after the decision to use the Fast Ethernet technology is minimal.
F ast Ether net 7-8 F ast Ether net Workgroup Design The Network Designer begins the design process by examining the available Fast Ethernet switch products.
F ast Ether net W orkgroup Design 7-9 F ast Ether net Figure 7-3. Fast Ethernet High-End Department Solution F ast Ethernet as a Backbone Due to the high throughput pr ovided by Fast Ethernet, it is conceivable that the technology could be used as a backbone solution to interconnect a series of workgroups.
F ast Ether net 7-10 F ast Ether net W orkgroup Design Figure 7-4. Initial Network Design Each departmental stack consists of one MicroMMAC-24E and one or mor e SEH-24 stackable hubs. In the initial configuration, the MicroMMAC-24Es have been configured with EPIM-A modules, which provide AUI ports for connection to a standard Ethernet AUI cable.
F ast Ether net W orkgroup Design 7-11 F ast Ether net The Network Designer examines the four types of FN100 Fast Ethernet switch, looking to see which models support front panel multimode fiber optic connections.
F ast Ether net 7-12 F ast Ether net W orkgroup Design Once the backbone switch has been selected, changes need to be made to the workgroups that will connect to the switch itself. As they stand, the current workgroups cannot connect to the Fast Ethernet backbone network.
8-1 Chapter 8 T oken Ring This chapter e xamines the decisions and selections that must be made when designing a T oken Ring workgroup solution. The process of designing a T oken Ring workgroup or a series of interconnected workgroups is somewhat dif ferent fr om the processes involved in designing an Ethernet or Fast Ethernet workgroup.
T oken Ring 8-2 T oken Ring Workgroup De vices The available devices and the main distinctions between them are summarized in T able 8-1. The columns in the table provide the same information that T able 6-1 provides regar ding Ethernet devices. The Port Count field, again, is independent of the PIMs/BRIMs field.
T oken Ring Workgroup Design 8-3 T oken Ring T oken Ring W orkgr oup Design Once a Network Designer understands the fundamentals of T oken Ring design, as described in the Cabletron Systems Networking Guide - MMAC-FNB Solutions , the design of a T oken Ring workgroup using standalone and stackable pr oducts is quite simple.
T oken Ring 8-4 T oken Ring W orkgroup Design Media It is assumed by this document that the selection of a networking media for the facility has already been completed befor e the hardwar e is examined.
T oken Ring Workgroup Design 8-5 T oken Ring This extension of the ring can be used to allow the T oken Ring network to connect widely-separated groups of stations in a single ring, or can be used to support greater numbers of users than a single T oken Ring stack can accommodate.
T oken Ring 8-6 T oken Ring W orkgroup Design When examining the Media characteristics of the devices remaining in the selection field, the Network Designer immediately eliminates the STHI-42/44 from consideration. The network being designed will use UTP cabling, which is not directly supported by the STHI-42/44.
T oken Ring Workgroup Design 8-7 T oken Ring Looking back at the initial selection field, the Network Designer locates the non-intelligent stackable devices and examines them for compliance with the needs of the network. The STH-22/24 non-intelligent stackable hub supports UTP cabling, and provides either 12 or 24 ports of station connectivity .
T oken Ring 8-8 T oken Ring W orkgroup Design.
A-1 Appendix A Char ts and T ab les This appendix provides a centr al location for a series of tab les that contain useful network design inf or mation. W orkgroup Design T ables Ethernet a. These products can be managed through the addition of an intelligent stackable de vice to their stack.
Char ts and T ab les A-2 W orkgroup Design T ables F ast Ethernet a. These products can be managed through the addition of an intelligent stackable de vice to their stack.
W orkgroup Design T ables A-3 Char ts and T ab les T oken Ring a. These products can be managed through the addition of an intelligent stackable de vice to their stack.
Char ts and T ab les A-4 W orkgroup Design T ables PIMs and BRIMs T able A-6. PIM Reference T able PIM T echnology Media Connector EPIM-A Ethernet AUI DB15 (Male) EPIM-C Ethernet Thin Coaxial RG58 EPI.
W orkgroup Design T ables A-5 Char ts and T ab les FPIM-00 FDDI Multimode Fiber Optics FDDI MIC FPIM-01 FDDI Multimode Fiber Optics SC FPIM-02 FDDI UTP RJ45 FPIM-04 FDDI STP RJ45 FPIM-05 FDDI Single M.
Char ts and T ab les A-6 W orkgroup Design T ables a. This table is subject to change as ne w BRIM modules and re vised firmware are released. T able A-7.
Networking Standards and Limitations A-7 Char ts and T ab les Netw orking Standar ds and Limitations Ethernet Distance Limitations General Rules T able A-9. Ethernet Standard Distance Limitations Media Max Distance Thick Coax 500 m Thin Coax 185 m Standard AUI 50 m Office AUI 16.
Char ts and T ab les A-8 Networking Standards and Limitations F ast Ethernet Distance Limitations Network Radii T able A-1 1. Fast Ethernet (100BASE-TX/FX) Distance Limitations Media Max Distance UTP 100 m Fiber Optics (Multimode) 412 m T able A-12.
Networking Standards and Limitations A-9 Char ts and T ab les T oken Ring Distance Limitations a. IBM T ype 6 cable is recommended for use as jumper cabling only , and should not be used for facility cabling installations.
Char ts and T ab les A-10 Networking Standards and Limitations Ring-In/Ring-Out Limitations General Rules T able A-14. Ring-In/Ring-Out Distances Media Max Distance (4 Mbps) Max Distance (16 Mbps) Shi.
Networking Standards and Limitations A-11 Char ts and T ab les FDDI FDDI Distance Limitations General Rules a. Category 5 UTP cabling only b . IBM T ype 1 STP cabling only T able A-16.
Char ts and T ab les A-12 Networking Standards and Limitations.
Glossar y-1 Glossary This glossary provides brief descriptions of some of the r ecurrent terms in the main text, as well as related terms used in discussions of the r elevant networking discussions. These descriptions are not intended to be comprehensive discussions of the subject matter .
Attenuation to Client-Server Glossar y-2 Attenuation Loss of signal power (measur ed in decibels) due to transmission through a cable. Attenuation is dependent on the type, manufacture and installation quality of cabling, and is expressed in units of loss per length, most often dB/m.
Glossar y-3 Coaxial to Decr yption Coaxial An Ethernet media type which consists of a core of electrically conductive material surrounded by several layers of insulation and shielding. Concentrator A network device which allows multiple network ports in one location to share one physical interface to the network.
Dedicated to F ault-T olerance Glossar y-4 Dedicated Assigned to one purpose or function. Device (netw ork) Any discrete electronic item connected to a network which either transmits and receives information thr ough it, facilitates that transmission and reception, or monitors the operation of the network directly .
Glossar y-5 FDDI to Impedance FDDI Fiber Distributed Data Interface. A high-speed networking technology . FDDI requir es that stations only transmit data when they have been given permission by the operation of the network, and dictates that stations will receive information at pr e-determined intervals.
Interf ace to MA C Address Glossar y-6 Interface A connection to a network. Unlike a port , an interface is not necessarily an available physical connector accessible through the fr ont panel of a device.
Glossar y-7 MA U to Network Radius MA U Multistation Access Unit. Mbps Megabits Per Second. Mbps indicates the number of groups of 1000 bits of data that are being transmitted thr ough an operating network. Mbps can be roughly assessed as a measur e of the operational “speed” of the network.
Node to Protocol Glossar y-8 Node Any single end station on a network capable of receiving, pr ocessing, and transmitting packets. NVRAM Non-V olatile Random Access Memory . Memory which is protected fr om elimination during shutdown and between periods of activity , frequently through the use of batteries.
Glossar y-9 PVC to Ser v er PVC Polyvinyl Chloride. A material commonly used in the fabrication of cable insulation. This term is used to describe a non-plenum rated insulating material. See also Plenum . PVC releases toxic smoke when burned. Redundant Extra or contingent.
SIMM to Switch Glossar y-10 SIMM Single In-line Memory Module. A collection of Random Access Memory (RAM) micropr ocessors which are placed on a single, r eplaceable printed circuit boar d. These SIMMs may be added to some devices to expand the capacity of certain types of memory .
Glossar y-11 TCP to UTP TCP T ransmission Control Pr otocol. T erminal A device for displaying information and relaying communications. T erminals do not perform any processing of data, but instead access processing-capable systems and allow users to contr ol that system.
UTP to UTP Glossar y-12.
Inde x-1 Index Numerics 100BASE-FX 2-3 100BASE-TX 2-3 A Active circuitry 2-6 APIM 4-5 Assistance 1-3 B Backbones collapsed 5-19 definition 5-17 device 5-20 distributed 5-18 Fast Ethernet 7-9 selectio.
Inde x Inde x-2 H Help 1-3 High-end department 6-19, 7-6 Home office 6-5 HubST ACK Interconnect Cables 3-5 I Installation planning 5-11 Interconnect cables 3-5 internetworking 4-8 Introduction 1-1 N .
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il Cabletron Systems bridges è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del Cabletron Systems bridges - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso Cabletron Systems bridges imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul Cabletron Systems bridges ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il Cabletron Systems bridges, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del Cabletron Systems bridges.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il Cabletron Systems bridges. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo Cabletron Systems bridges insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
