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LAN 102: Network Hardware And Assembly

LAN 102: Network Hardware And Assembly
By

Tom's Hardware and Que Publishing are partnering up to give you four chapters from Scott Mueller's Upgrading And Repairing PCs, 20th Edition. This forth installment is a continuation of the third chapter we're making available from Scott's book, which covers Local Area Network (LAN) hardware and assembly. Don't forget to check out the previous chapters published on Tom's Hardware, Computer History 101: The Development Of The PC, Hard Drives 101: Magnetic Storage and LAN 101: Networking Basics. In the days to come, we'll also present a comprehensive look at Power Supplies.

The choice of a data-link protocol affects the network hardware you choose. Because the various flavors of Ethernet and other data-link protocols use different hardware, you must select the architecture before you can select appropriate hardware, including NICs, cables, and switches.

NICs for Wired Ethernet Networks

On most computers, a wired Ethernet network adapter is integrated into the motherboard. If the integrated component fails or is not fast enough, a replacement NIC can be added through the PCI or PCI Express slot (desktop computers), USB, CardBus PC Card (PCMCIA), or ExpressCard slot on a laptop.

Network adapters (both wired and wireless) have unique hardware addresses coded into their firmware. The hardware address is known as the MAC address. You can see the MAC address on a label on the side of the adapter, or you can view it after the adapter is installed with an OS utility such as the Windows ipconfig.exe command. The data-link layer protocol uses these addresses to identify the other systems on the network. A packet gets to the correct destination because its data-link layer protocol header contains the hardware addresses of both the sending and receiving systems.

Most motherboards have wired Ethernet adapters built-in, whereas discrete Ethernet network adapters range in price from less than $10 for client adapters to more than $100 for single or multiport server-optimized adapters.

Although you can connect two computers directly to each other via their Ethernet ports with a crossover cable, larger networks need a switch, which is frequently incorporated into a router. The network runs at the speed of the slowest component, so if you use a switch that runs at a slower speed than the network clients, the clients connected to that switch will run at that slower speed. Many wireless routers now include 1000 Mb/s gigabit Ethernet ports instead of slower 100 Mb/s Fast Ethernet ports.

When connecting systems on wired Ethernet networks, the following sections contain my recommendations on the features you need.

Speed

Your NIC should run at the maximum speed you want your network to support. Most gigabit Ethernet and Fast Ethernet cards also support slower speeds, meaning, for example, that a 1000 Mb/s (gigabit Ethernet) card also supports 100 Mb/s (Fast Ethernet) speed or standard Ethernet’s 10 Mb/s speed, allowing the same card to be used on both older and newer portions of the network. To verify multispeed operation, look for network cards identified as 10/100 or 10/100/1000 Ethernet. All modern Fast or gigabit NICs should also support full-duplex operation:

  • Half-duplex means that the network card can only send or only receive data in a single operation.
  • Full-duplex means that the network card can both receive and send simultaneously. Full-duplex options boost network speed if switches are used in place of hubs. For example, 1000 Mb/s gigabit Ethernet cards running in full-duplex mode have a maximum true throughput of 2000 Mb/s, with half going in each direction.


Note: Unlike hubs, which broadcast data packets to all computers connected to them, switches create a direct connection between the sending and receiving computers. Therefore, switches provide faster performance than hubs; most switches also support full-duplex operation, doubling the rated speed of the network when full-duplex network cards are used.

For more information about switches, see Scott Mueller's Upgrading And Repairing PCs, 20th Edition, “Switches for Ethernet Networks,” p. 816 (this chapter).

Bus Type

If you need to install a network adapter for use with a gigabit Ethernet (10/100/1000 Mb/s) network, any of the following buses have more than adequate performance:

  • PCI/PCIe. The integrated NIC built in to most motherboards are either PCI or PCIe devices.
  • CardBus/ExpressCard (laptop computers).


All of these buses support gigabit Ethernet adapters without limiting throughput. Integrated network adapters use either the PCI or PCI Express bus to connect to the system, both of which have more than enough bandwidth. Note that USB 2.0 (480 Mb/s) is not on that list because it is simply not fast enough to fully support gigabit Ethernet’s 1000 Mb/s bandwidth; however, 100 Mb/s Ethernet connections will work on USB 2.0 with no problems. USB 3.0 would be more than fast enough to support a gigabit Ethernet adapter, however there aren’t any network adapters I know of using USB 3.0.

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  • 5 Hide
    JasonAkkerman , November 2, 2011 4:37 AM
    Lots of good information there. Lots of history too.
  • 0 Hide
    KelvinTy , November 2, 2011 7:45 AM
    O... I thought all CAT5 are able to transmit 1000Mbps signals BEFORE reading this article... It's kind of weird ~_~" that I can get 5.X MB/s download speed = ="
  • 4 Hide
    Reynod , November 2, 2011 10:28 AM
    Don could you talk to Chris A and Joe and see if we could give a few hard copies of this book away as prizes for some of our users here in the forums who work hard to help others?

    How about a copy for each of the users who make the top ranks for the month of November ... under the Hardware sections of the forums?


    :) 
  • 0 Hide
    Anonymous , November 2, 2011 1:12 PM
    mixer device
  • 2 Hide
    JasonAkkerman , November 2, 2011 1:18 PM
    They make it look like making a cable it so easy, and it is, after the first few tries. Also, making one or two cables isn't too bad, but don't let yourself get talked into making 50 two foot patch cables. Your finger tips will never forgive you.
  • 0 Hide
    thrasher32 , November 2, 2011 1:45 PM
    Great information.
  • 0 Hide
    xx_pemdas_xx , November 2, 2011 1:57 PM
    JasonAkkermanThey make it look like making a cable it so easy, and it is, after the first few tries. Also, making one or two cables isn't too bad, but don't let yourself get talked into making 50 two foot patch cables. Your finger tips will never forgive you.

    I got talked into making 10...
  • 1 Hide
    spookyman , November 2, 2011 2:11 PM
    JasonAkkermanThey make it look like making a cable it so easy, and it is, after the first few tries. Also, making one or two cables isn't too bad, but don't let yourself get talked into making 50 two foot patch cables. Your finger tips will never forgive you.


    Oh I don't know. I have made several thousand patch cord over the past 18 years.

    All you need is a high quality crimper, good cutters and small screw driver. You are set.
  • 2 Hide
    silveralien81 , November 3, 2011 2:56 AM
    This was a great article. In fact it inspired me to buy the book. I'm happy to report that the rest of the book is just as well written. Very educational. A top notch reference.
  • 2 Hide
    neiroatopelcc , November 3, 2011 10:27 AM
    Read the first page. Seems like well written stuff, but not exactly written for my type of user. Also it seems to be igoring a lot of stuff. For instance it sais the network runs at the speed of the slowest component and will figure it out on its own. This isn't true. If you run a pair of 1000TX capable nics on old cat 5 cable (without the e), it'll still attempt to run at that speed, despite the massive crc errors it might generate. Also, if you're running on 'old gigabit hardware' it won't nessecarily have support for 10Base-T speeds. Also, not all firmware has autonegotiate or automdix support, thus you sometimes have to specificly set the speed between links. This is mainly for fiber links though, which seem to have been ignored entirely.

    Anyway. As I said, I think it's well written and probably quite suitable for people who don't know anything about networks (except it seems to assume people know the osi model). I'll go see if the other chapters are equaly basic.
  • 0 Hide
    fixxxer07 , November 4, 2011 1:28 AM
    kelvintyO... I thought all CAT5 are able to transmit 1000Mbps signals BEFORE reading this article... It's kind of weird ~_~" that I can get 5.X MB/s download speed = ="


    5 MBps = 40 Mbps... so it's not that weird. xD
  • 0 Hide
    dthurber , November 4, 2011 2:00 PM
    Great article with lots of information. The crossover cable mentioned would work for 10/100, but for gigabit ethernet you must also crossover the blue and brown pairs. Unlike 10/100 ethernet, gigabit ethernet uses all eight conductors.
  • 1 Hide
    cangelini , November 4, 2011 7:59 PM
    reynodDon could you talk to Chris A and Joe and see if we could give a few hard copies of this book away as prizes for some of our users here in the forums who work hard to help others?How about a copy for each of the users who make the top ranks for the month of November ... under the Hardware sections of the forums?


    Heya Reynod,

    We had access to 10 copies of it for a contest that ran with the first few pieces of the book, but those were given away already.

    I agree that it's a great idea to reward the most active forum users, though. I'll get together with Joe and see if there's anything we can do there!

    Have a great weekend,
    Chris
  • 0 Hide
    Reynod , November 6, 2011 11:28 AM
    Thanks Chris.

    I feel a bit stupid now I missed it.

    It would be great if you could do something again though.

    I did PM Don Saturday to ask him.

    Cheers

  • 0 Hide
    neiroatopelcc , November 21, 2011 6:06 AM
    patch cables of those small lengths you just buy readymade - they're more sturdy anyway, and you can get them as any cable type (cat5e, 6a etc) .. and long's you don't add old cat5 or mix shielded with unshielded, cables really are the least difficult part of network building - although cisco want you to believe otherwise.
  • 0 Hide
    juanc , November 25, 2011 2:18 PM
    completely amazed at how many errors are in page 2
  • 0 Hide
    juanc , November 25, 2011 2:33 PM
    Either I'm missing to read something or the article on page 3 does not note, that to make Patch Cables you must use a different type, multi-filament copper cable instead of the standard in-wall one-wire solid copper conductors that get cut when you crimp. Huge mistake
  • 0 Hide
    juanc , November 25, 2011 2:44 PM
    Shielded twisted pair (STP) refers to the amount of insulation around the cluster of wires

    There is no "amount" it does have a shield.

    it was first thought that shielding the cable from external interference was the best way to reduce interference and provide for greater transmission speeds. However, it was discovered that twisting the pairs of wires is a more effective way to prevent interference

    No. Shielding is better. But the trick on twisting is that we are talking about "differential" signals. If not, twisting would be useless. Twisting to cables cancel each others emissions and emissions from other places to the cable are canceled too.

    10GBE pros say you should not wire UTP but only STP.

    Need cable lengths longer than the lengths you can buy preassembled

    Never buy preassembled cables. Can't assemble cable as I said before on mono-filament cable.
    One filament wires can't be twisted or take turns or >90 degrees. There's a big chance they can break. Can't wire thru a pipes with the RJ45 plug on it.

    Use Jacks. Buy machine assembled/tested multi-filament patch cords from the jack to the computer/router/printer/switch, whatever.
  • 0 Hide
    Slothy , January 13, 2012 11:57 PM
    I read this article as it was linked in the power supply guide posting, which I thought (on perusing it quickly) seemed rather well done. However, this article is so attrocious (both in inaccuracies and it's horribly outdated information) that it draws into doubt the quality of the original article that brought me here. I'm not just some Joe going off on a rant without knowing a thing, and my apologies as I am sure that this was likely intended for average Joe who doesn't have a strong base in networking, but even for that, it could have been written immensely better. I don't know if the author is to blame or the technical editor.

    First off, as a disclaimer, I didn't bother reading the wireless section. Stuff has been changing too rapidly the past few years to even bother, and it is ultimately so simple nowadays that you shouldn't even have to bother with the wireles options. What I did see of wireless information (such as range) was horribly inaccurate. In my experience with most indoor environments, you'll be lucky if you get a *reliable* signal at a fraction of the 150 feet he mentions.

    Simple advice for wireless: Buy a dual-radio N-capable wireless router and then decide if you're going to use N-capable internal wireless cards or USB dongles for any devices you have that do not include integrated wireless. Be warned that in my experience, many wireless routers designed for home use work fine for wireless devices accessing the internet, but when attempting to transfer data between a wired and wireless device, the router will act as a bottleneck, often running at speeds lower than what standard (10 Mbps) ethernet will provide. If you plan on hooking up a device such as a home server or NAS device to your home wireless router, be careful what you pick and either fork out the money for a higher-end SOHO/SMB device or read your reviews thoroughly and ensure that you're getting exactly that device (down to the revision number even, sometimes).

    This article clutters the users mind with unnecessary information and technical details which to knowledgeable persons will already be apparent, and recognized as often incorrect; and for the unknowegeable reader - incorrect and irrelevant but taken as true. To rattle off a few
    -switches and hubs, while sharing some features (they're small, blockish and have multiple ports) are also different at an operational level - switches are OSI layer 2 devices, while hubs are electrical devices operating at OSI layer 1.
    -Packets do not get where they need to go because of MAC addresses; frames get where they need to go thanks to MAC addresses while packets are at OSI layer 3 and utilize IP addresses for routing.
    -If you want to see your MAC address via ipconfig, use ipconfig/all. ipconfig on its own will not provide you with this information.

    If I wanted to take a closer read or go through it again, I'm sure I could pull out atleast as many errors as I listed above, but I've gotten enough of my steam out about someone publishing yet more outdated and erroneous technical info or advice in the realm of networking and IT. Please, if you're going to write a tech article, do it with a purpose, stay true to it, make sure you have your stuff down pat, and damn well update it if you're going to re-publish it.

    No one cares about coaxial ethernet anymore, unless you're over the hill or working in some industrial environment with networked machinery, in which case I hope you're not getting your expertise from this article.

    PS. I'd still like to say thanks to Tom's Hardware and that they're an invaluable resource - not just for their reviews and articles, but for the user community they have generated as well. But with that said - is it just me, or is Tom's IT site just one big stream of advertisements in the guise of articles, news stories, and white papers?
  • 0 Hide
    Anonymous , August 8, 2012 4:38 AM
    why are you using blue and brown wires even though they are of no use?