Fiber Optics in the LAN and Data Center

[Music] um [Music] we're going to explore the complex world of fiber optics in the local area network and in the data center fiber optics and the local area network share many concepts and components of today's data centers the local area network has been stuck for years we're still using cat5 cat5e if you're lucky cat6 and if you're really lucky cat6a twisted pair copper and we're still delivering about one gig to most desktops very few people are getting more than one gig at the desktop that should start to move as desktops start coming with multi-speed network cards and as enterprises start buying multi-speed switches as if they drop in price you'll begin to see 2.5 gigabits to the desktop eventually five gigs and i feel at some point we'll see 10 gigs to every desktop when it comes to fiber fiber is exploding it is the go-to connectivity component of the future local area networks typically use for switch uplinks from idfs to mdfs from servers to high-capacity server network cards to switches that are using say 10 gig and higher but when we get into the data center fiber is being used almost exclusively because we're typically wanting 100 to 400 gigabits on uplinks 25 to 50 gigabits to servers and at least 10 gigabits to virtual machines fiber is exploding in the data center and that explosion will move into the local area network two broad categories of fiber cable and the local area network and the data center one is optical single mode which is called os cable optical multi-mode which is called om cables and this has to do with the size of the core single mode core is about 8 to 10 microns whereas multi-mode can be 6.25 which is old to the newer 50 micron core sizes fiber optic core size is really important single mode fiber cable uses a small core 8 to 10 microns this requires more expensive electronics and more expensive lasers but it gives us higher bandwidth and longer distance on the other hand multi mode has a larger glass core about 50 microns and it allows us to use cheaper electronics and cheaper lasers drives down that cost so that we can use it more effectively as a tool for networking this chart shows the relative size comparison between single mode glass core the multi-mode glass core and the old 62.5 multi-mode glass core notice though that there is a lighter blue around the darker blue that's the cladding that is bonded to the glass and notice that all three have exact same size so when you add the cladding to the glass you get in all three types of cable you get 125 microns this is om1 fiber optic cable it's legacy it is remember oms is optical multi-mode the jacket color is orange it has a coarse side of 62.5 microns has a maximum data rate of about one gigabit when we install this in 1995-96 we were told at that time this will never become obsolete it's obsolete om3 fiber optic cables are laser optimized multi-mode the jacket color is aqua the core size is 50 microns with a single fiber we can get about 10 gigs using about the 850 nanometer wavelength distance is about 300 meters now if you switch to the connector that's at the top right which is an mpo connector with multiple fibers we can start getting about 40 gigabits even up to 100 gigabits but our distance drops down to about 100 meters let's take a look at this chart this is an ethernet chart showing us interfaces and speeds versus the type of optic cables that we can use notice at the top you've got one gigabit and that's pretty well where you're stuck with om1 om2 cables as you get into om3 we can see that we can get up to about 10 gig and that's if we're using an lc or an sc connector down as you've come down further you'll see 40 gigabits of ethernet we can use a multi-mode om3 cable but we have to move to that mpo connector we can see sliding down further 100 gigabits we can still use the om3 cable but again we have to use that mpo connector and i'll talk about those connectors in a minute om4 fiber optic cable improved over the om3 it allows us basically the aqua collar jacket the 50 micron core size 10 gigabits for a single fiber using the the 850 nanometer wavelength distance and that's the advantage of the om4 is the distance you can see we're up to about 550 meters so the advantage of this this particular cable is longer distance as we look at om1 to om4 cable standards it's important to also remember different industry groups apply different nomenclatures so i've got a chart showing you the iec's nomenclature for each of the cable types t-i-a-e-i-a's nomenclature and then on the right shows you the loss of light per kilometer at different wavelengths notice at the lower frequencies 850 nanometers all of these cables lose about 3.5 db per kilometer that's why these cables do not work well for long distances 3.5 db is half of your power every kilometer this is unacceptable for long distances problems that face fiber optics are light loss this is something that every network administrator has to consider very carefully as he chooses cables and connectors is how much light is lost from the transmitter to the receiver you can see in this diagram below you can actually see the transmitter and the pulses of light going down the fiber optic cable and you notice that as we travel down the cable light is lost and the signal height is slowly growing smaller and smaller as we reach a connector we see there's a significant loss of light and again as the light signal travels down the fiber optic cable again there's a constant loss of light this optic light budget is something that you must calculate to make sure from the transmitter to the receiver you have enough light to get there om 3 and 4 fiber optic cables are both laser optimized multi-mode fiber and were developed to accommodate faster networks for 10 40 and 100 gigabits both were designed for use with the nanometer vertical cavity surface emitting lasers and they have aqua jacket colors due to the need of longer distances om4 plus an enhanced version of the om-4 cable is now being produced and its jacket color is violet it allows the same bandwidth but it allows signals up to 300 meters [Music] [Applause] [Music] [Applause] [Music] so [Music] in the video that i just finished on os osi layer 2 the wan technologies i covered dense wave division multiplexing which is giving us terabits per second but it's using single mode fiber optics there's also available for single mode fiber optics coarse wave division multiplexing which is giving us incredible bandwidth and distance for this technology also but again it's using single mode fiber optics if you would like a review on that technology you can go to my channel and look at the osi layer 2 looking at the wan and its technologies so in order to bring this wavelength division multiplexing technology to multi-mode om5 was developed now we're going to introduce short wavelength division multiplexing so that we can get some of those great features that we have in single mode now we can use them in multi mode so om5 is our newest fiber optic cable its jacket color is lime green it's fully compatible with om3 and om4 it uses a wide range of wavelengths between 850 nanometers and 953 nanometers it's designed to support short wavelength division multiplexing which allows us to get 40 to 100 gigabits over a single fiber single mode cable provides 50 times more the distance and multi multi-mode cable does it typically used in high bandwidth applications and long-haul networks especially telecommunications and data centers here we have os 1 and os2 remember this is optical single mode fiber versions one and two we see the itu standard nomenclature we see the application one indoor one outdoor we see the attenuation per kilometer take a look at that os2 has almost half the attenuation per kilometer that os one the l the distance you can see definitely a difference in distance price goes with the territory inside the data centers we'll see a lot of os1 outside the data centers we'll see a lot of os2 a quick review of fiber jacket colors based on the type of cable that we have om1 and 2 is going to be orange jacket om3 and 4 is aqua unless we're dealing with om4 plus is going to be a violet and then os os1 and os2 is yellow now since we're on the subject of jacket colors there are non-standard cable colors many manufacturers make fiber optic cables in non-standard colors so just be aware of that also some manufacturers will match a certain color code to the connector body and the strain relief based on the fiber optic cable you're using they're not every manufacturer does not hold to this but some do and it makes it real easy to locate and identify the cable and the type of cable if all this detail about fiber optic cables wasn't enough both the national electrical code and local building codes dictate the type of material that makes up your jacket on your cable let's take a look plenum is an important concept for it professionals most of us work in buildings where we have hanging ceilings and above the hanging ceilings is a place where cables are typically run this is where you have your air conditioning duct work this is known as a plenum if you have a false floor where you have air space and you have cables running in that area also that is also known as a plenum the riser is the vertical areas of the wall where you have cables going up from the floor to the ceiling or from the first floor to the second floor that is known as a riser the national electrical code as well as local buildings code dictate the type of jacket that has to be on your cables in order to reside in those spaces all network cable whether it's cat5 cat6 cat6a or fiber optics all come with a certain makeup of jacket material whether it's pvc which is commonly used in the workspace or polyurethane it could be polyvinyl difluoride which is very flame resistant depending on where you put your cables this is fiber or twisted pair you have to be aware of the local fire code and national electrical codes as to what kind of jacket material can go in plenums risers or in the workspace if you put the wrong kind of cable in the wrong space the fire marshal can shut your facility down pvc is a common jacket material but it gives off heavy black smoke and a toxic fume low smoke zero halogen cable is flame retardant and is used between buildings floors in a building optical fiber non-conductive plenum cable is almost self-extinguishing in terms of flames so all these are just three of the many types of jacket material you need to be aware of this most cable installers know what to put where but too often someone's trying to save some money and starts throwing fiber optic or twisted pair cables in the wrong location it could cost you a raise maybe your job so i'm on a typical cable retail website and you can see i can see the types of cable i can see this is pvc this is lsch this is ofnp that tells me the type of jacket that this fiber optic cable is made of so i know where that that cable can go and where it can't go here's another retail site for fiber optic cables and you can see it's very plain this is plenum rated this is riser rated indoor outdoor so they're trying to make it as easy as possible this is important so this is an example of a cable riser in a new data center you can see it's solid concrete all the electrical communication network cables run through this multi-story building risers provide a fire safety barrier between the potential electrical fires and people in the building i'll leave this chart with the latest nec code with their designations descriptions cable applications in the notes you can take a look at it next connectors here are two some of the most popular fiber optic connectors in the business sc connector all fiber optic connectors have a lock in place so once you press them into their position they lock in place the sc connector is older the lc connector is without a doubt the most popular connector in fiber optics the sc connector was developed by nippon telegraph and telephone ntt remember they all have a snap and lock connector this one has excellent insertion loss it's the second most common fiber connector if you see one connector that's called simplex if you see two gang together with a connector that's a duplex if you'll notice down here when i'm looking to purchase connectors or cables you'll see sc to sc cable om4 so i know that this has an sc2sc connector on one end sc connector on the other hands down lc connector is the most popular connector in fiber optics it has a 1.25 millimeter ferrule that's the ceramic piece that protrudes out of the connector that's what actually holds the fiber optics the lc has a latch design that offers a pull proof stability administrators love that feature here we see an lc and sc connectors when they're locked together they're sold locked together that's called a duplex in other words it has both transmit received fiber optic cables connected and locked together when you have a single connector and cable that's called a simplex these two fiber optic connectors are legacy but you will find them out there in the wild st connector uses a bayonet locking system kind of like a bnc if you're familiar with that cable connector then you have the fc connector which is actually a screw on mating threads used in high vibration environments the mu connector is very popular especially in dense environments where we have a lot of density and fiber optic connectors the ls8 is another one used in telcom and dwdms the mu connector is square and employs that push-pull mating mechanism it has a great locking system very popular in japan and asia used for sonnet sdh lan wdm catv and atm if you take the comptia net plus you'll be forced to make to learn this particular connector it's called the mtjr connector it has never really took off it's got a lot of high insertion loss and it's avoided by many equipment manufacturers so it's there be aware of it you may be tested on it but you probably won't see it used very often the newest kit on the block is the cs connector by cinco it's half the size of an lc connector remember that's real popular it's designed for the next gen 200 400 gig transceivers which i'll talk about both of those and you can see on the bottom left you can see the comparison between the lc connector and the c cs connector we'll see whether it gains traction in the data center world time will tell keeping the ferrule or the tip of the fiber optic connector clean is a very important feature that brings us to the e2000 connector it has an integrated spring-loaded shutter it just kind of falls right over the top of the ferrule protects it from dirt dust and scratches this is liked in the industry especially in single mode it has a very low return loss of over 0.1 db and is one of the lowest in the industry data centers are driving for more fiber optic density and that's where these two connectors come in the mtp and the mpo fiber connectors allow up to 24 fiber optic connections made with one connector as you look closely at the face of this connector this is an mpo multiple fiber push-on connector mpo and mtp although mtp was made by a different manufacturer they are compatible they're all about fiber density they commonly have either 12 fibers or 24 fiber arrays in each plug the next generation connector will have 16 to 32 fiber arrays this will be required for 400 gigabits each mpo connector is either male with pins or female without pins to ensure alignment of the fiber and faces during mating also notice there's a key up portion of the connector mpo and mtp connectors can be used in many many ways one is you can create a straight through cable where pin one goes to pin one pin two goes to pin two this is often used on patch base and remember you're bringing 12 to 24 fibers at one time another typical use for the mpo is a crossover cable pen one to pin 12 pin 2 to pin 11. this is typically used on switches transceivers and other electronic gear now there are other methods of using these cables but these are two of the most important often you want to take an mpo connector and break it out into individual fibers so if you look at this little cassette it's a 1u rack cassette and basically you put your mpu plug on the rear of the cassette and you can see how the top has been lifted off and you can see all the fiber strands have been exposed mated to an lc connector in the front [Music] [Applause] [Music] [Applause] uh surely mr vanderpool we've learned everything we ever need to know about fiber optic cables no not quite the fiber connector tips or the ferrule you can see in the picture i've got different ceramic tips that protrude out of the connector these are called pharaohs there are more than one type so we have the pc or the physical contact ferrule and it's slightly beveled and polished the next one is the upc the ultra physical contact it is more polished it gives a better contact less loss of light then the one that is used often in single mode fiber optics is the angled physical contact what has an 8 degree bevel when choosing fiber optic cables not only do you have to have the right jacket the right jacket material what fire code does it meet what type of cable is it what type of connector but you also need to know what how the ferrule is designed connectors have different feral designs that's the two ceramic pieces that butt up together during the connection the pc connector allows them to meet and the end faces are polished to be slightly curved or spherical this eliminates air gap and forces the fibers into contact lower optical return loss and back reflection is about negative 40 db this diagram carefully exaggerates the problem that the ferrule design is supposed to solve notice the gap interval between the two fiber optic connectors obviously that's quite a distance and that's exaggerated but it gives you the idea that the engineers are facing if there's any gap at all there's going to be light loss and less light go down the existing connector that's butted up against it so this is the problem that they're facing these feral designs are to address these problems this diagram really helps you understand the challenge that electrical and optical engineers face as they design connectors for the optical systems you can see the very first connector where the laser transmitter is sending the light we've already talked about the loss of the signal as it goes down the fiber and then when it hits that first connector boom you can see a drastic loss of light and a continuation of loss as it goes down but look at the arrow that goes back this is reflected light back to the transmitter is going to interfere with the existing signal it's going to distort it then after the connector we see the light going down to the last connector where the receiver is and again we see reflection going back and then look when it hits the the middle connector we see the second return of light back this is going to compound our degradation of the signal as we get in past this first connector the design of these connectors is no easy task for these engineers upc ferrule connectors are the most popular in network switches and data communication the end faces are given an extended polishing for a better surface finish back reflection are reduced even more to about negative 55 db the apc fiber connector referral connector is the latest technology it's called the angle physical contact connector the end faces are still curved and polished but they're angled at about an 8 degree tilt this maintains a tight connection reduces back reflection to about negative 7 db which is very good these connectors are preferred for single mode catv and hd video systems make sure you never mate an apc ferrule with a upc ferro connector if you do it will it will cause poor performance but most likely it's gonna damage the connectors this is the heart of the fiber optic system in the lan and in the data center they're called transceivers these tiny devices are the electrical optical magic that is key to fiber optics today let's take a look at the transceiver basics basically we have electronic input it goes into a driver that drives an led or laser creates a series of light pulses down the fiber optic cable it is detected by a photo detector of some type it's amplified and turned back into electronic output that's what a transceiver is going to do optical transceivers are critical to local area networks and data center it is important you understand the components or the specifications of optical transceivers we're going to look at size electrical lanes optical lanes heat dissipation this is important as we get into single mode cost and then what type of fiber does it does it work with does it work with single mode fiber or multi-mode sfp is is one of the most popular form factors for transceivers it begins by requiring a slot a plug-and-play slot that's usually mounted on a circuit board you see these in switches routers network cards and they allow the transceiver to be inserted and connect some designs allow things like optical transceivers or transceivers with an rj45 jack you can also find sfp slots that allow dac or direct attach cables these are very desirable in low latency transmission or active optical cables aoc all of these can plug into a sfp slot transceivers take electrical signals on one end as we plug it into the slot and they turn it into optical signals on the other electrical signals like ethernet 10 25 50 and 100 gigabits per second or infiniband or fiber channel the optical side is typically a variety of infrared wavelengths or short wavelength division multiplexing keep in mind all parallel all data within a computer is parallel data that is how we're getting the computing power of a pc or a server but when you hit a transmission line like an optical line or a twisted pair we have to convert that to serial in order to get high speed ethernet or high-speed optical lines we have to convert that parallel data to serial and that's what serializer deserializer asic chips do they're called surdes and it's functional blocks commonly used in high-speed communication to compensate for limited input output these asic chips are very expensive to develop and in fact you look at this transceiver it requires four of these running at 28 gigabits per second in order to produce an optical fiber line of 112 gigs the greatest limitation for optical fiber transmission is the electronics not the optical let's walk through the build of a newest fiber transceiver is 100 base sr qfsp28 transceivers one the latest greatest so this is the inside of an optical transceiver and remember we're looking at only the transceiver portion of an optical transceiver there's also a receiver in there so you see the electrical contacts we're assuming there's the asic chip that does the serializing deserializing connected to the asic chips are the laser diodes they're going to create our our nanometer wavelengths next is the cooling mechanism to cool the laser diodes to maintain stable wavelength light transmission this is very important especially in single mode next to the lasers are the lenses that are going to focus the light in the direction of the fiber cable next we're going to use those lenses to tune precise wavelengths which are critical in the optical transmission after the lenses we're going to put an optical multiplexer this optical assembly is not only going to do the multiplexing but it's also going to remove all unwanted wavelengths so only the most precise wavelengths are going out there so optical trans transceivers have both transmitters and receivers so now this is the receiver light is coming into the receiver now the optical light is going to go into our optical demultiplexer assembly and this is going to have mirrors that reflect light and send certain wavelengths to colored filters which will allow only prescribed wavelengths to pass we'll now focus that demultiplex light that light is now sent to pin diodes that transmit translate light into electrical signals we finally send that into an amplifier and it goes out the printed circuit board this is a great block diagram of what's taking place in the latest greatest transceivers that are available today based on the designs that you just saw these are some of the fevers that are on the market today some of these transceivers run over two thousand dollars each let's look at these three transceivers and better understand why the diversity that we see here at the top we have 40 gig transceivers with a om4 cable between them and they're using lc connectors and you can see that's pretty much the same down with all three transceivers in the middle we have 100 gig transceivers and at the very bottom we have a 100 gig transceiver at the top let's look at the top 10 gigs coming in on each side we're taking remember we have to do this serialize deserialize those asic chips are very expensive the lower the speed the less expensive they are and so a lot of times 40 gigs is a choice reduces the cost of the transceiver if i want higher speeds such as in the center then i have to bump up my asic chips inside one of my problems with that is i get higher power requirements more heat dissipation so four 25 gig electrical lines converted into optical lines can be pricey in terms of heat and wattage dissipation so here you see at the bottom we've kind of gotten rid of those four and we went to 250 gigs the trouble is the asic chips to do that are more expensive we're probably using less power less wattage dissipation but the price goes up it is common to use high bandwidth transceivers to break out into many lower bandwidth transceivers so on the left you see a transceiver that has an mpo connector and it's 100 gigs let's say that's a switchboard and i'm actually taking a cable called a breakout cable to four lc connectors and i'm going into 25 gig transceivers say each of those are going into servers our classical use of optical transceivers and fiber in a local area network is to uplink one switch to another as you see in this picture so where is optical fiber going where's the future the ieee is not able to produce standards fast enough for the industry and the speed that they desire so you're seeing pop up groups like the optical internet working forum this is a group of industry people who are developing agreements between themselves to advance optical networking right now we're seeing 100 to 600 coherent laser modulator driver receivers that are being developed today here's an example of that technology and you can actually see its size against the euro [Music] thank you [Music]

Channel: Lowell Vanderpool

Views: 218,723

Rating: 4.9145947 out of 5

Keywords: Fiber optics, LAN, Data Center, OM1, OM2, OS1, OS2, OM3, OM4, OM5, transcievers, single mode, multimode, MPO, MTP, LC, ST, SC, Polish type

Id: fRKT6Z9rgUw

Length: 31min 26sec (1886 seconds)

Published: Mon Mar 02 2020