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Structured Ca ...and the KRONE These days, it’s an unusual business that doesn’t have its computers networked. But there are networks – and networks. How can today’s organisation install a network that not only gives the performance required but also the flexibility to cope with change, growth, and emerging technologies? The answer lies in structured cabling. F irst, though, a network story that would almost make you cry. I can guarantee the veracity because I was there. Recently, a large firm of architects decided to move offices. They had occupied a whole floor of a city building with perhaps sixty or so computers networked via Cat5 cable (see “What is Cat5” panel). I was offered some of the office furniture that was surplus to requirements so went in one Saturday morning to get what I wanted. Ahead of me was an electrician, removing not just all the electrical wiring but all of the network and telephone cabling. The way he was doing this was simple: cut it off into small lengths and reef it out! We started talking about this incredible waste but he wasn’t too perturbed. The opposite, in fact: he said “hey, when the new tenants move in they’ll call me to put all this stuff back in again. I win both ways!” To make matters worse, he told me that this was by far his major source of income. “I do it all the time as companies move offices,” he said. “Sometimes they’re not even moving but reorganising, moving people around internally. You’d be amazed at how much stuff they put in, then pull it all out six months later!” 70  Silicon Chip While I would hate to see a sparkie done out of a job, all this wastage (to me) borders on the criminal. And the pity of it all is that it could all be avoided with a structured cabling system. Most new buildings are being cabled this way but it’s just as viable for existing buildings, especially when the occupants want to upgrade. Done once, it doesn’t need to be done again. What is a structured cabling system? Put as simply as possible, it’s a method of installing data and communications cabling which allows total flexibility by remaining fixed in place. Huh? OK, we acknowledge that’s a bit of a difficult concept to follow. How can a cabling system that is fixed in place allow total flexibility? Let’s take a typical scenario in a large company. Jane Smith has earned her promotion and moves into the manager’s office. Good news for Jane but now she has a different office, a different phone and possibly fax number. She plugs her computer into the wall socket and finds… nothing. Her by ROSS TESTER computer cannot talk to the network because the socket isn’t wired. Now the network administrator has to make a whole lot of changes, all Jane’s workmates have to change their telephone lists, the receptionist needs to remember the change . . . It’s all pretty simple stuff of course but it’s all very disruptive and costly. And don’t forget John Smith who has moved into Jane Smith’s old office, with a new telephone and fax number. At least his computer will talk to the network because Jane’s used to plug in there! Or another example: many organisations today use workgroups to tackle particular tasks or contracts. When that task or contract is complete, the members of that workgroup are disbursed to different workgroups to take on new tasks. Again, locations change, phone numbers change, computers move. It’s the above situation all over again but multiplied by the number of people involved. Wouldn’t it be nice if Jane and John Smith’s phone and fax numbers and computers (ditto everyone in the workgroup) could stay the same regardless of where they were physically located in the organisation? In other words, their “electronic” address(es) stayed exactly the same, abling Systems E “MiniLAN” Making changes to the phone, fax, network or other communication lines is so simple it’s almost child’s play. This particular version of the KRONE MiniLAN uses punch-down connectors but it could be just as easily loaded with plug’n’play couplers. regardless of their physical location. socket(s) close by, just waiting to be one point, a “switchboard”, of sorts, where the signal paths can be directed They can – with a structured ca- plugged in. and changed virtually at will. It is bling system. That’s at the worker’s end. But this ability to change which gives the Part of the secret is that when the the major feature of the structured network (or PABX system) is installed, cabling system is at the other end of system its flexibility. those cables. They all go back to the In fact, the word “switchboard” is every office, every possible location quite a good analogy. where a worker will be For those old enough located (eg, a desk or a to remember manual workstation) is pre-wired • Any service – telephone (voice), fax, data and even audio tele­p hone exchanges – just in case it will ever and video can be made available to any outlet as required. (Silvester switchboards) be used. where subscribers were Now if this seems like a •  Changing those services or re-routing to another outlet can connected by a switchbig waste of cable, in the be achieved within minutes. girl (sorry to be sexist but overall scheme of things •  The heart of a structured cabling system is the ability to they were almost always adding a few tens or even interconnect or “patch” cables together as required. girls!) who plugged lines hundreds of metres of •  Data rates of 100 megabits per second and more can be into appropriate cables cable in the installation achieved now – and as technology pushes speeds higher, on the board, that’s exphase costs a whole lot structured cabling can handle it actly what happens with less than trying to fix a structured cabling things up later – and then •  Old and new systems (or protocols) can be handled with system. paying for the disruption! ease. This means that an organisation does not need to When someone moves Every office, every desk update a complete system but can do it gradually. offices, all the network location has its own Structured Cabling in Summary: August 2000  71 TO ANOTHER NETWORK OTHER SERVICES IN (DIGITAL OR ANALOG) PHONE, FAX LINES IN administrator needs to do is swap the patch lead from its current location (the socket connected to the cable which went to Jane Smith’s old office) to the socket which connects to her new location. Exactly the same thing applies to her phone and fax lines: simply swap a couple of patch leads. The same simple solution applies with John Smith. He is “patched” through to his new location. No change of addresses or numbers, no problems – Jane and John Smith have moved but their business lifelines have moved with them – with little or no disruption. 72  Silicon Chip It looks just like a typical network – except for that box in the middle. It’s the heart of a structured cabling system and allows changes to be made virtually at will without re-wiring. The system is not limited to work-stations; it can also be used for shared equipment. A lot of equipment – printers, scanners, etc – is now appearing with network identification codes, making these devices “intelligent” as far as a network is concerned. They don’t even need to be connected to a PC – just plugged straight into the network. Believe it or not, there are even such things as intelligent video cameras which have their own ID – you can log on to these (eg, for security applications) as you would any other device with a network ID. These intelligent devices are called “network appliances” (that’s one of the new industry buzz-words you’re going to hear a lot more of!). You’re probably thinking that what we’ve been describing so far is for large organisations, Government departments and the like. But now structured cabling systems are also eminently suitable for SMEs (small to medium enterprises). With the right equipment, a structured cabling system is an elegant, cost-effective solution for the data and communications needs of any sized business – even the small office/home office (SOHO). Don’t you just love all these acronyms? Closed (left) and open (above) views of the KRONE MiniLAN before any cabling. This one has two 24-way patch panels (OK, one is a 23way because it’s missing a coupler!) as well as a modem on the shelf. As you can see, there’s plenty of space for more devices including another patch panel if you wish. It’s all up to you and your needs. The KRONE MiniLAN The KRONE MiniLAN, distributed by Namlea Data Systems (NDS), is an excellent example of the “heart” of a structured cabling system. Where large companies, government departments and so on might require a room-sized installation, the MiniLAN is the solution for small businesses. That’s not to say those larger organisations don’t have applications for the MiniLAN: remember those workgroups we talked about before? The MiniLAN is the perfect method for connecting a workgroup back into a large organisation’s mainframe. Perhaps even more importantly, it allows a mixture of protocols on the same network (protocols describe the way computers talk to each other over the network). A MiniLAN can provide the gateway for a network operating on one protocol to talk to another (perhaps larger, older) network. And as we said above, it also allows such things as printers, scanners and other network equipment to be placed Two types of RJ-45 jack, showing the difference: on the left is a “coupler” which is in fact two back-to-back jacks. These are used only with patch cords. On the right are two “punch-down” jacks (front and rear) which require connection with a special punchdown tool to solid core Cat5 LAN cable. wherever convenient – exactly the type of flexibility large organisations have been demanding. The point is that the MiniLAN and structured cabling make perfect partners for any organisation with changing requirements – whether those requirements are current work practices, future expansion – anything. The MiniLAN is small – just 301 (W) x 371 (H) x 102 (D)mm. Something this small can be mounted just about anywhere – anywhere that’s convenient to bring the cabling into. It’s suitable for wall or desk mounting. What makes the MiniLAN exciting though, is not its size nor its versatility. For the first time it is possible for anyone with a minimal knowledge of computer operation to change not only the network but telephone services as required. Until now, at least in the case of telephones, that’s been illegal. To change the position of a phone or a number in a business, you’ve had to call in an Austel-approved cabling installer who would make the necessary changes to your system and charge you accordingly. Because you’re not touching any of the wiring – it stays exactly where it was originally installed – you can quite legally make wholesale changes to the system. All you are doing is changing the positions of patch leads which make the connections to that wiring. As long as you can read the labels on the sockets and follow simple colour coding, you’re in business! Now you can see what makes MiniLAN such a boon for business. As well as avoiding the disruption of the person moving, you’re also avoiding the disruption of moving everything associated with the person. MiniLAN makes it that easy. You may have noticed that we have been freely mixing up computer networking and telephone circuits in this discussion. That’s deliberate – because MiniLAN can handle both at the same time. It can also handle audio, low-resolution video and more. Inside the MiniLAN The MiniLAN is designed to hold one, two or three 24-port patch panels (it is supplied with one of these patch panels fitted). There is also a shelf designed to accommodate all of the data/communications interconnectivity equipment required – a modem (or perhaps two), network hubs or August 2000  73 What is “Cat5”? As you may have realised, Cat5 is shorthand for Category 5. But what is this category and are there other categories? The cable categories you will find in general use are Cat3, Cat4 and Cat5. There are others, of course, but they won’t concern us here. These are all types – categories – of unshielded twisted pair (UTP) cables. As that name suggests, the pairs of insulated conductors within a cable are twisted together. Cat5 UTP has eight insulated conductors, twisted tightly together in four pairs. By the way, the pairs of insulated conductors or indeed the whole cable can also be shielded – known as STP, or shielded twisted pairs. STP is not as commonly used in Australia. You have probably seen and used Category 3 cable many times. Standard 4-core telephone cable is Cat3. As data cable, its use is limited to “low speed” 10-BaseT networks of 10 megabits per second or less. It is quite rare to find Cat3 cable used in data installations these days – but it is occasionally used. Cat4 cable is only marginally better than Cat3 – it is suitable for up to 16 megabits per second. It was originally used in Token Ring networks. Cat5 cable takes a massive leap forward in speed – up to 100 megabits per second and more. And now there is a new “enhanced” version – Cat5E , the so-called “Gigabit Ethernet” which is rated at 1000 megabits per second (1GB). Cat5E is only slightly more expensive than standard Cat5 so for new installations, looking towards the future, it is by far the better proposition. Here when we refer to Cat5 it could be either Cat5 or Cat5E. The MiniLAN, by the way, performs to Cat5E specifications. The outer insulation of Cat5 cables is almost always light blue. There are two types of Cat5 cable – one has a solid core and is intended for permanent installation (ie, in the wall or in ducts); the other has multiple conductors and is intended for patch cables. The first type is referred to in the trade as LAN cable, the second as patch cable. It is important not to use one in place of the other not just because of flexibility but also because of the connectors used. Cat5 is almost never soldered to – connectors are virtually always a crimped type. In the RJ-45 wall jacks or sockets an IDC (insulation displacement connection) is used, where the connection is made to each of the solid-core wires by tiny blades which pierce the wire’s insulation and grip the outsides of the wire. This is also known as “punched down” – the special tool to perform this action and terminate the wires is called a punch-down tool. Conversely, most RJ-45 plugs are designed to connect mainly to patch leads. In this case, a sharp point pierces the insulation and separates the multi-strands inside, making contact with many of them. This highlights one of the most-often-made mistakes with Cat5: using the wrong type of plug with the wrong type of cable. This problem is overcome by using ready-made leads (in fact, with telephone services, Austel rules require you to use approved (therefore pre-made) cables. Cat5 has a standardised colour scheme where the pairs of cables within the outer sheath can be easily identified. There are four basic colours – blue, orange, green and brown. The other cable of each pair has the same main colour along with a white stripe, or is white with the main colour as a stripe. Pair one, therefore, is blue and white/blue; pair two is orange and white/orange; pair three is green and white/green and pair four is brown and white/brown. Each of the pairs is assigned to a particular pair of pins on the modular connector so as to miminimse the chance of interference between the various transmit/receive pairs. There is one main standard used in Australia, 568A. This has pair one connected to pins four and five, pair two to pins three and six, pair three to pins one and two and pair four to pins seven and eight. Finally, there are limits on the lengths you can run Cat5 cable – the usual rule is 90 metres of LAN cable and up to ten metres of patch cable at each end – a total of 100 metres overall. If you think 100 metres is a long distance, you might be surprised just how much is used when running cable, especially when run around offices, up (or down) partitions and so on. Some brands of Cat5 LAN cable have their length back to the start of the roll printed on them every metre – that’s handy when you’re installing long lengths and want to know how much cable you have left! Wiring of Cat5 to an RJ-45 jack or plug following the Type 568A standard, the one most usually found in Australia. 74  Silicon Chip routers, internet gateways and so on. Each of the patch panels can be loaded with as many keystone inline jacks as required (up to the 24 maximum). The RJ-45 jacks (also called modular connectors) themselves can be either the traditional “punchdown” variety which has one side pre-wired and permanently connected (in the case of phone lines, by a licensed Austel installer) or can be double-ended which means both sides have RJ-45 jacks and use patch leads to connect on both sides (more correctly called “couplers”). What you use depends to a large degree on where you site the MiniLAN. Ideally, it should be close to where your phone lines come in, then patch leads and couplers can be used. If some distance away, your phone lines will need to be extended (by a licenced installer) and terminated to RJ-45 sockets. The major point is that once the phone lines are terminated to the back of the MiniLAN you don’t need to go there again. Everything is now done from the front. To use an oft-misused term, the MiniLAN is plug’n’play – you plug in, then play (or work!) Colour-coded jacks are available which tell at a glance what service is what. You can get red, blue, white, black, green, yellow and grey. What are all the colours used for? Well, Cat5 cabling is not limited to phone, fax or data. You can also run audio over Cat5 and even low-resolution video (eg, from the CCD cameras now available). Other reasons to use different colours are to divide the area into workgroups or sections (eg, marketing has black, warehouse yellow, and so on). The back of the MiniLAN is open, allowing completely unfettered entry of all cables. The front is protected by a hinged perspex door with just enough “smokiness” to camouflage (but not hide) what’s inside. It’s quite an attractive package. Installation Your first step is to decide how big a system you will be installing and for what purpose. Remembering what we said before about the future, it’s better to go too big than too little. Think of how much you’d like your business to grow in future – then add another 50% margin just in case you’re really successful! A typical Krone MiniLAN setup with the patch panel at top patched through to a 8-port network hub, thence to an internet gateway (bottom) and then a 56k modem, giving a full shared internet connection to multiple users. “RJ” jacks and plugs The industry refers to the modular plug and jack system as “RJ” . While possibly a misnomer (RJ more correctly refers to a cable standard), that’s what they’re commonly known as so   that’s what we’ll call them. The jack is the wall-mounted or floor-mounted socket, or   female connection, one of which is pictured above. The plug is the male connector which inserts into the jack (as pictured below). The 4-pin modular plug most commonly associated with telephones is known as a 4P4C, or four position four contact (even though in telephones only two are required and often only two are connected, which could be described as 4P2C). The RJ-11 and RJ-12 connectors are 6-position sockets used for voice applications. They're commonly used on answering machines. 6P2C sockets have two contacts wired (usually the middle pair), 6P4C have four contacts wired while 6P6C have all six contacts wired. The RJ45 connector is actually an eight-position socket. It is almost always loaded with all eight contacts wired (8P8C) but for specific uses can be wired with two contacts (8P2C), four contacts (8P4C), or six contacts (8P6C). RJ-11 and RJ-12 plugs can usually be inserted into an RJ45 jack but there is some danger of distorting the socket (due to insufficient sideways support). This may result in an unreliable connection. Incidentally, Telstra has recently announced             that they plan on standardising on an RJ45              socket for all new telephone installations. August 2000  75 The two different Cat5 cables in use and the two types of wall outlets: here we have LAN Cat5 wired through ducting to a pair of surface-mount boxes containing RJ-45 jacks (left) while the photo at right shows a surface-mounted double RJ-45 jack with a PATCH Cat5 cable going off to its device. You also need to decide which services will be connected through your MiniLAN and how you’re going to identify them. Take phone lines, for example: most businesses use a PABX or at least a Commander-type system. There’s nothing at all to stop you wiring these lines via the MiniLAN, just as there is nothing to stop you wiring direct or dedicated lines (fax/modem lines, for example). Note that installation of the lines from the street or from your PABX/ Commander system to the MiniLAN must be done by an Austel-licensed installer. But once they’re in place, you can route them as you wish. You would normally use one panel (or perhaps one area of a panel in a small installation) for your incoming services and another panel (or area) for your LAN connections, phone lines, etc. By the way, you aren’t limited to data and phone connections – the same cabling can be used for building security, audio distribution and even low-res video. However, there are limitations in using the cabling for a number of services due to interference between adjacent pairs of wires within the cable (crosstalk arguably being the worst problem). There are various ways in which these problems can be minimised – for example the amount of individual wire untwisted from the Cat5 cable must be carefully controlled. You may be wondering, as we did, if you want to run different services over the various pairs of conductors within the Cat5 – how do you do it? The answer here is to use a splitter – it doubles the capacity by separating out the cables into two RJ-45 sockets. You could therefore run two phone lines – one voice, one data; two data; or two voice over the same cable. 76  Silicon Chip Having said that, though, if you want to ensure top performance it is better to install additional Cat5 cables (at time of original installation) to run other services, especially if you’re going for high-speed or organisation-critical data. Running Cat5 I’ve installed a fair bit of cabling over the years – everything from unforgiving heavy-duty coax for amateur antennas to burglar alarm sensor wiring in impossible-to-reach places and even run kilometres of figure-8 up and down beaches for PA systems. But I have to say that Cat5 has to be the most ornery (cable) critter I’ve ever come across. I’m sure that Cat5 is what Murphy’s Law (or more specifically, his first cable corollary) was written for: the more impossible it is for a cable to tangle, the more certain it is that the cable will develop a tangle of monumental proportions; or the less likely a cable can possibly get caught on a snag, the more likely it will! Having said that, installing Cat5 cable is not dissimilar to installing any other type of cable. However, you should keep in mind that the wires in Cat5 for permanent installation in the wall or ducts (called Cat5 LAN) always have single solid conductors so it doesn’t take too kindly to kinking, stretching or jerking. Nor should you install it where it can be stepped on or chafed on tight corners nor curved too tightly in radius, which can degrade performance. If you have to pull Cat5 too hard (eg, to get it through a wall cavity) the holes it’s going through are probably too small. On a long distance run, if you have the choice (ie access), make the pull in two halves: pull it part way, then pull it through the rest of the way. Cat5 cables for patching have multi-wire conductors for flexibility because they are designed to be moved around. Having said that, though, they should still be treated with due care! You can choose a variety of mounting methods and locations for the wall or outlet jacks (sockets) for your Cat5 LAN. Standalone surface mount boxes are available for areas away from the wall. On walls you can use either those boxes or, for a neater appearance, jacks are available which will snap into standard Clipsal/HPM style wall plates (the same as those used for light switches) in one, two, three or four jack-to-the-plate configurations. Terminating Cat5 to modular sockets will usually require the use of a special cable stripper to remove the other insulation (or sheath) without damaging the inside cables. Then you’ll almost certainly need a punchdown tool to anchor the individual conductors correctly into the back of the socket, This is not difficult to do but before you try it for real, practise on some Cat5 offcuts! You can make Cat5 patch leads yourself – but why bother? They’re readily available in a wide variety of lengths and colours – and if the length of lead you want isn’t available “off the shelf”, companies such as NDS can make them to order. By the way, if you’re considering a MiniLAN or any other LAN installation, it’s well worth getting hold of a copy of the NDS catalog – it has a great deal of network information as well as all the products you’re going to need. Call (02) 9429 0800 and they’ll send SC you a copy, free of charge. Acknowledgement: Much of the information and some of the photographs and illustrations are courtesy of Namlea Data Systems.