20:
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239:. Even if not partitioned automatically, a hub simplifies troubleshooting because hubs remove the need to troubleshoot faults on a long cable with multiple taps; status lights on the hub can indicate the possible problem source or, as a last resort, devices can be disconnected from a hub one at a time much more easily than from a coaxial cable.
272:
100 Mbit/s hubs and repeaters come in two different classes: Class I delay the signal for a maximum of 140 bit times. This delay allows for translation/recoding between 100BASE-TX, 100BASE-FX and 100BASE-T4. Class II hubs delay the signal for a maximum of 92 bit times. This shorter delay allows
214:
must be followed: up to five segments (four hubs) are allowed between any two end stations. For 10BASE-T networks, up to five segments with four repeaters are allowed between any two hosts. For 100 Mbit/s networks, the limit is reduced to three segments between any two end stations, and even
263:
the 10 Mbit/s and 100 Mbit/s segments. When a network device becomes active on any of the physical ports, the device attaches it to either the 10 Mbit/s segment or the 100 Mbit/s segment, as appropriate. This obviated the need for an all-or-nothing migration to Fast
Ethernet
242:
To pass data through the repeater in a usable fashion from one segment to the next, the framing and data rate must be the same on each segment. This means that a repeater cannot connect an 802.3 segment (Ethernet) and an 802.5 segment (Token Ring) or a 10 Mbit/s segment to 100 Mbit/s
209:
The need for hosts to be able to detect collisions limits the number of hubs and the total size of a network built using hubs (a network built using switches does not have these limitations). For 10 Mbit/s networks built using repeater hubs, the
293:
Historically, the main reason for purchasing hubs rather than switches was their price. By the early 2000s, there was little price difference between a hub and a low-end switch. Hubs can still be useful in special circumstances:
215:
that is only allowed if the hubs are of Class II. Some hubs have manufacturer-specific stack ports allowing them to be combined in a way that allows more hubs than simple chaining through
Ethernet cables, but even so, a large
154:
is repeated to the output of every other port except for the port of entry. Specifically, each bit or symbol is repeated as it flows in. A repeater hub can therefore only receive and forward at a single speed.
193:. A hub cannot further examine or manage any of the traffic that comes through it. A hub has no memory to store data and can handle only one transmission at a time. Therefore, hubs can only run in
339:, the first Ethernet-over-twisted-pair standard, was announced in 1986. Its successor, the Starlan 10, was announced in 1987. By 1994, the industry had started to shift to switching.
160:
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The transmission path permitted between any two DTEs may consist of up to five segments, four repeater sets (including optional AUIs), two MAUs, and two AUIs.
595:
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devices connected then the whole network needed to run at 10 Mbit/s. Therefore, a compromise between a hub and a switch was developed, known as a
617:
251:
In the early days of Fast
Ethernet, Ethernet switches were relatively expensive devices. Hubs suffered from the problem that if there were any
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is generally more robust than coaxial cable-based
Ethernet (e.g. 10BASE2), where a misbehaving device can adversely affect the entire
150:
A layer 1 network device such as a hub transfers data but does not manage any of the traffic coming through it. Any packet entering a
201:, packet collisions are more likely in networks connected using hubs than in networks connected using more sophisticated devices.
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As hubs have lower latency and jitter compared to switches – as long as there are no collisions – they may be better suited for
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networks. These devices are considered hubs because the traffic between devices connected at the same speed is not switched.
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internally consist of two hubs with a bridge between them. Since every packet is repeated on every other port, packet
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682:
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104:
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A hub with both 10BASE-T ports and an AUI port can be used to connect a 10BASE5 segment to a modern network.
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314:
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A hub with both 10BASE-T ports and a 10BASE2 port can be used to connect a 10BASE2 segment to a modern
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Most hubs detect typical problems, such as excessive collisions and jabbering on individual ports, and
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it works by repeating transmissions received from one of its ports to all other ports. It is aware of
120:
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92:
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but commercial products have failed to appear due to the industry's transition to switching.
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232:
142:. As of 2011, connecting network segments by repeaters or hubs is deprecated by IEEE 802.3.
8:
482:
348:
328:
733:
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481:
Charles
Spurgeon (2000-02-16). "Chapter 13: Multi-Segment Configuration Guidelines".
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appears at the output of every port except the original incoming. A hub works at the
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network is likely to require switches to avoid the chaining limits of hubs.
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99:. A repeater hub also participates in collision detection, forwarding a
211:
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100:
619:
Ethernet POWERLINK Communication
Profile Specification. Version 1.4.0
35:
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the port, disconnecting it from the shared medium. Thus, hub-based
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24:
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A network hub is an unsophisticated device in comparison with a
88:
189:) and sense a collision which it also propagates by sending a
683:"Switching strategy will be key as internet markets collide"
517:"What is the difference between Class I and Class II hubs?"
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the installation of two hubs in a single collision domain.
112:
108:
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affect the entire network, limiting its overall capacity.
596:"Sniffing Tutorial part 1 - Intercepting Network Traffic"
259:. These devices make use of an internal two-port switch,
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into a network connection, a hub is an alternative to a
134:
Hubs are now largely obsolete, having been replaced by
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41. Repeater unit for 1000 Mb/s baseband networks
438:
27. Repeater unit for 100 Mb/s baseband networks
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9. Repeater unit for 10 Mb/s baseband networks
335:One of the first Ethernet hubs, the HP Starlan for
79:devices together and making them act as a single
616:Ethernet Powerlink Standardization Group (2018),
725:
480:
405:
403:
401:
568:
281:Repeater hubs are defined in the standards for
663:"HP's 10Mbit/sec. LAN needs no special wiring"
123:(AUI) connector to allow connection to legacy
541:Network Maintenance and Troubleshooting Guide
468:Networking: A Beginner's Guide, Fifth Edition
398:
598:. NETRESEC Network Security Blog. 2011-03-11
461:
459:
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181:packets, that is it can detect their start (
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16:Device for interconnecting Ethernet devices
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115:") ports, some hubs may also come with a
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34:
18:
222:
726:
575:About This Particular Macintosh blog
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375:are sometimes called switching hubs.
138:except in very old installations or
276:
156:
13:
43:connector and eight 10BASE-T ports
14:
750:
699:
246:
569:Matthew Glidden (October 2001).
267:
675:
655:
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91:introduced at the input of any
75:device for connecting multiple
538:Neil Allen (18 October 2009).
510:
484:Ethernet: The Definitive Guide
474:
470:. McGraw Hill. pp. 68–69.
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430:
418:
389:
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1:
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103:to all ports if it detects a
39:8-port Ethernet hub with one
27:Ethernet hub with selectable
519:Intel. Retrieved 2011-03-16.
7:
414:. Delmar. pp. 256–257.
342:
10:
755:
412:Network+ Guide to Networks
395:IEEE 802.3-2012 Clause 9.1
315:Ethernet-over-twisted-pair
107:. In addition to standard
139:
121:Attachment Unit Interface
651:. 1986-11-06. p. 6.
643:"HP adopts Starlan plan"
466:Hallberg, Bruce (2010).
359:
205:Connecting multiple hubs
140:specialized applications
87:(I/O) ports, in which a
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146:Physical layer function
197:mode. Due to a larger
44:
32:
410:Dean, Tamara (2010).
233:twisted-pair Ethernet
38:
22:
528:IEEE 802.3 Clause 41
223:Additional functions
739:Networking hardware
571:"Switches and Hubs"
349:Router (computing)
329:Ethernet Powerlink
325:real-time networks
131:network segments.
83:. It has multiple
65:multiport repeater
45:
33:
494:978-1-56592-660-8
300:protocol analyzer
185:), an idle line (
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373:Network switches
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298:For inserting a
283:Gigabit Ethernet
277:Gigabit Ethernet
237:collision domain
199:collision domain
136:network switches
73:network hardware
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157:Dual-speed hubs
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81:network segment
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700:External links
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257:dual-speed hub
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247:Dual-speed hub
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691:. 1994-02-21.
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688:Network World
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671:. 1987-08-31.
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714:. Retrieved
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627:, retrieved
625:, p. 35
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611:
600:. Retrieved
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578:. Retrieved
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498:. Retrieved
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85:input/output
68:
67:, or simply
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61:repeater hub
60:
56:
52:
49:Ethernet hub
48:
46:
448:IEEE 802.3
436:IEEE 802.3
424:IEEE 802.3
304:network tap
195:half duplex
57:network hub
728:Categories
716:2021-12-01
629:2019-05-06
602:2011-03-13
500:2012-01-08
383:References
243:Ethernet.
212:5-4-3 rule
191:jam signal
172:multiport
161:collisions
101:jam signal
53:active hub
229:partition
105:collision
29:MDI-X/MDI
734:Ethernet
343:See also
317:network.
261:bridging
253:10BASE-T
183:preamble
174:repeater
77:Ethernet
25:10BASE-T
580:June 9,
354:USB hub
337:StarLAN
327:, e.g.
170:. As a
129:10BASE5
125:10BASE2
41:10BASE2
23:4-port
711:GitLab
552:
491:
168:switch
119:or an
89:signal
623:(PDF)
360:Notes
71:is a
582:2011
550:ISBN
489:ISBN
289:Uses
152:port
113:RJ45
109:8P8C
93:port
31:port
306:or
127:or
117:BNC
69:hub
47:An
730::
709:.
685:.
665:.
645:.
573:.
548:.
544:.
503:.
487:.
456:^
400:^
111:("
63:,
59:,
55:,
51:,
719:.
605:.
584:.
558:.
331:.
310:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
