Speaker 1: So every time you double tap a photo on your
Speaker 1: phone to like it, you're actually unknowingly triggering this really
Speaker 1: strict Cold War era military protocol.
Speaker 2: Yeah, it's wild to think about.
Speaker 1: Right, Like that tiny action chops your tap into these
Speaker 1: microscopic data packets, scrutinizes them through intelligent intersections, and then
Speaker 1: you shoots them via lasers through hair thin tubes of
Speaker 1: glass across the ocean, and all of that in just
Speaker 1: a matter of milliseconds.
Speaker 2: Which is frankly a brilliantly constructed illusion of simplicity because
Speaker 2: the moment you look beneath that frictionless glass screen while
Speaker 2: you find this world of uncompromising traffic laws and literal
Speaker 2: light speed logistics.
Speaker 1: I mean, we interact with this invisible architecture constantly streaming,
Speaker 1: working whatever. Yeah, but we almost never see the sprawling
Speaker 1: physical infrastructure making it happen. It just feels like magic, exactly.
Speaker 2: But every single piece of data has to navigate a
Speaker 2: highly organized gauntlet to get from point A to point B.
Speaker 1: And today we are going to demystify that exact gauntlet.
Speaker 1: Welcome to today's deep dive.
Speaker 2: Glad to be here.
Speaker 1: Our mission today is to take you on the exact
Speaker 1: journey your data takes from the physical cables in your
Speaker 1: wall all the way up to the invisible rules governing
Speaker 1: the global web.
Speaker 2: And to map this out, we are diving into excerpts
Speaker 2: from Todd Lamley's CCNA Certifications Study Guide, Volume.
Speaker 1: Two, Yeah, which is basically the definitive blueprint for understanding
Speaker 1: the nuts and bolts of networking.
Speaker 2: What makes this material so compelling is that it focuses
Speaker 2: heavily on the why. You know. It reveals the sheer
Speaker 2: human ingenuity required to solve massive logistical problems.
Speaker 1: Because networking did not start out organized, did it.
Speaker 2: Not at all? The rules and devices we used today
Speaker 2: they evolved out of absolute necessity to prevent digital traffic
Speaker 2: from just collapsing under its own weight.
Speaker 1: So let's start right there at the physical intersections, you know,
Speaker 1: the devices that act as the traffic cops for our data.
Speaker 2: Right. The transition from hubs to switches to routers. It's
Speaker 2: really a story of moving from total chaos to highly
Speaker 2: targeted communication.
Speaker 1: Yeah. Because in the early days, if you wired a
Speaker 1: small office together, you plug everything into a hub. And
Speaker 1: I mean a hub is about the dumbest piece of
Speaker 1: hardware imaginable.
Speaker 2: It really is. It operates with zero intelligence, right, It just.
Speaker 1: Takes an electrical signal coming in on one wire and
Speaker 1: blindly copies it to every other connected wire.
Speaker 2: Yeah. So if a hub receives a message meant for
Speaker 2: one specific computer, it just blasts that message out to
Speaker 2: fifty other computers anyway.
Speaker 1: Which causes a massive problem.
Speaker 2: Exactly, an electrical problem. If two devices connected to that
Speaker 2: hub try to talk at the exact same fraction of
Speaker 2: a second, they're electrical signals physically crash into each other
Speaker 2: on the wire. Oh wow, Yeah, the data becomes corrupted,
Speaker 2: the transmission fails, and both computers have to pause for
Speaker 2: a random amount of time before trying again.
Speaker 1: And that is what the industry calls a single collision domain.
Speaker 2: Right, yes, exactly.
Speaker 1: I always picture a hub like a guy at a
Speaker 1: crowded party. If he wants to tell a secret to
Speaker 1: one person, he doesn't walk over and whisper.
Speaker 2: He grabs a megaphone.
Speaker 1: Yes, he grabs a megaphone and shouts it to the
Speaker 1: entire room. Everyone has to stop their conversation, listen to
Speaker 1: the megaphone and figure out if the message is for them.
Speaker 2: And if two people shout at once, no one understands anything. Right.
Speaker 1: You can imagine how quickly a network grinds to a
Speaker 1: halt if fifty computers are constantly shouting over each other.
Speaker 2: So to fix that literal shouting match, network engineers introduced switches,
Speaker 2: which are much smarter, way smarter. A switch actually pays
Speaker 2: attention to who is talking to whom. It uses specialized
Speaker 2: hardware called application specific integrated circuits or ASEX, which process
Speaker 2: data at blistering speeds. Wait, yeah, ASEX. The moment a
Speaker 2: computer plugs into a switch, the switch memorizes its physical
Speaker 2: hardware address, its MBSC address, and logs it into a
Speaker 2: dedicated filter table.
Speaker 1: Okay, so it turns the chaotic megaphone room into like
Speaker 1: a polite cocktail party.
Speaker 2: Exactly, people are having private one on one conversations.
Speaker 1: So when computer A sends a file to computer B,
Speaker 1: the switch checks its filter table and forwards that electrical
Speaker 1: signal exclusively to the single port where computer B is
Speaker 1: plugged in. Nobody else hears it.
Speaker 2: Right, it successfully breaks up the collision domains. Everyone can
Speaker 2: talk simultaneously without their signals interfering. But switches introduce a
Speaker 2: new vulnerability. Oh really yeah, because they are designed to
Speaker 2: forward a very specific type of traffic called a.
Speaker 1: Broadcast, Right I remember reading about that.
Speaker 2: Sometimes a computer legitimately needs to ask the entire local
Speaker 2: network a question like who has this specific IP address?
Speaker 2: The switch will dutifully take that broadcast question and copy
Speaker 2: it to every single.
Speaker 1: Port, which sounds fine until your network grows. Yeah, because
Speaker 1: if you have thousands of devices occasionally shouting questions to
Speaker 1: the entire room, you create a broadcast storm exactly.
Speaker 2: The network gets so bogged down processing everyone's general questions
Speaker 2: that actual data just stops moving.
Speaker 1: And that brings us to the bouncer at the door,
Speaker 1: the router.
Speaker 2: The router is key. Routers operate on a completely different
Speaker 2: level of logic. Instead of looking at physical mix addresses,
Speaker 2: they read logical IP addresses, and their.
Speaker 1: Default behavior is to relentlessly block local broadcasts. Right.
Speaker 2: Yes, If a packet hits a router and it is
Speaker 2: addressed to everyone on this local network, the router drops
Speaker 2: it immediately, so.
Speaker 1: The writer stands at the exit of the party. It
Speaker 1: breaks up those broadcast domains so that local chatter doesn't
Speaker 1: deafen the entire Internet.
Speaker 2: Precisely, if you want to talk to a device in
Speaker 2: the room next door, meaning a completely different network. You
Speaker 2: have to go through the bouncer, So.
Speaker 1: You contain collisions with switches and you contain broadcasts with routers.
Speaker 2: Makes sense, right, And once those foundational intersections are in place,
Speaker 2: the challenge shifts to scale.
Speaker 1: Moving from a single room to a massive corporate campus
Speaker 1: or a data center.
Speaker 2: Yeah, that requires a structured architectural model to keep all
Speaker 2: those switches and routers organized. The classic approach is the
Speaker 2: three tier model.
Speaker 1: Which is this beautifully logical hierarchy broken into three layers, access, distribution,
Speaker 1: and core.
Speaker 2: Correct. The access layer is where you, the user, actually interact.
Speaker 1: With the network, like where my desktop computer plugs directly
Speaker 1: into an.
Speaker 2: Access switch exactly. Its only job is to get you
Speaker 2: connected and enforce basic port security. Above that sits the
Speaker 2: distribution layer, which is essentially the brains of the entire
Speaker 2: campus network.
Speaker 1: This is where the heavy duty routing happens, right.
Speaker 2: Yeah. It connects all the various access switches together, apply
Speaker 2: security policies, enforces access lists, and ultimately directs your traffic
Speaker 2: toward the top of the pyramid.
Speaker 1: Which is the core layer. And the core layer is
Speaker 1: all about pure, unadulterated.
Speaker 2: Speed, nothing but speed. The source material stresses that you
Speaker 2: should never ever put a firewall or an access list
Speaker 2: in the core layer.
Speaker 1: It's like a massive data highway. You do not put
Speaker 1: a toll booth in the middle of the autobox.
Speaker 2: Great analogy. Its only job is to switch massive volumes
Speaker 2: of data as fast as physically possible.
Speaker 1: You know, I was looking at the section on network designs,
Speaker 1: and it also details a collapsed core setup, yeah, which
Speaker 1: intentionally combines the core distribution layers into one device. I mean,
Speaker 1: if the core is supposed to be this sacred, blazing
Speaker 1: fast highway with no rules, why would anyone deliberately bottleneck
Speaker 1: it by bogging it down with distribution duties.
Speaker 2: Well, it's a perfect example of engineering meeting economic reality.
Speaker 2: Building a true three to two network requires purchasing highly specialized,
Speaker 2: tremendously expensive hardware, So it's the money thing. Completely. A
Speaker 2: dedicated core switch that does nothing but move data at
Speaker 2: wire speed costs of fortune. For a small to mid
Speaker 2: size business. Their daily data volume rarely justifies that kind
Speaker 2: of capital.
Speaker 1: Expenditure, so they compromise to save the budget. They collapse
Speaker 1: the brains in the highway into a single physical box. Right.
Speaker 2: They lose that theoretical maximum top speed. But for a
Speaker 2: fifty person company, it is still more than fast enough
Speaker 2: to get the job done. Practicality off and wins out.
Speaker 1: But as we move from corporate offices into modern cloud
Speaker 1: data centers, the three tier model starts to show cracks,
Speaker 1: doesn't it.
Speaker 2: It does. In a traditional office, traffic flows north south.
Speaker 2: You sit at your desk, request a file from a server,
Speaker 2: and the file comes back down. But in a massive
Speaker 2: data center powering something like a streaming service, the servers
Speaker 2: are constantly talking directly to each other, sinking databases and
Speaker 2: sharing workloads. That's east west.
Speaker 1: Traffic and pushing east west traffic up and down. A
Speaker 1: three tier pyramid creates a massive bottleneck.
Speaker 2: Exactly. That is why modern data centers use a spine
Speaker 2: leaf architecture.
Speaker 1: In this setup, every leaf switch, which sits at the
Speaker 1: very top of a server rack, connects directly to every
Speaker 1: single spine switch in the room.
Speaker 2: It creates a highly predictable environment where any server can
Speaker 2: talk to any other server in exactly one hop. The
Speaker 2: latency is virtually non existent.
Speaker 1: But that instant unhindered access introduces a terrifying security risk.
Speaker 2: Right, oh, absolutely, If every server can reach every other server, instantly.
Speaker 2: A malicious virus can infect the entire data center in milliseconds, which.
Speaker 1: Is why the architecture evolved to include next generation firewalls
Speaker 1: or ngfw's like Cisco's Firepower.
Speaker 2: Yes, these are light years beyond the old firewalls that
Speaker 2: just checked a port number and an IP address.
Speaker 1: Right. A traditional firewall is like a security guard just
Speaker 1: checking if your name is on the guest list. A
Speaker 1: next generation firewall actually opens the envelope, reads the letter,
Speaker 1: and decides if the contents are a threat.
Speaker 2: That's a great way to put it. It performs deep
Speaker 2: packet inspection, utilizing intrusion prevention systems to hunt down malicious
Speaker 2: code hidden inside normal looking traffic.
Speaker 1: It uses Application visibility and control.
Speaker 2: Right yes, AVC. It understands the context of what you're doing.
Speaker 2: It knows the difference between you logging into a cloud
Speaker 2: storage site to read a document versus trying to covertly
Speaker 2: upload proprietary company data, and.
Speaker 1: It can block the upload while allowing the read access.
Speaker 1: That's incredible. So we have these highly intelligent intersections, massive
Speaker 1: architectural grids, and incredibly paranoid security guards.
Speaker 2: But none of this functions without the physical roads.
Speaker 1: Right. I was looking at the section on unshielded twisted
Speaker 1: pair or UTP cabling. This is the standard copper Cat
Speaker 1: six cable you probably have plugging into the back of
Speaker 1: your WiFi.
Speaker 2: Radder, the standard workhourse of networking.
Speaker 1: And it honestly blew my mind that the eight tiny
Speaker 1: copper wires inside are twisted together not for durability, but
Speaker 1: to utilize literal physics to cancel out electromagnetism.
Speaker 2: It is an incredibly elegant analog solution to a digital problem.
Speaker 1: How does that actually work?
Speaker 2: Well? When electrical signals travel down parallel copper wires, they
Speaker 2: generate tiny electromagnetic fields. If those wires sit flat next
Speaker 2: to each other, the fields bleed over and corrupt the
Speaker 2: data on the adjacent wires. We call that.
Speaker 1: Cross stock ah crosstalk.
Speaker 2: Yeah, But by tightly twisting the pairs together, the opposing
Speaker 2: electromagnetic fields perfectly cancel each other out. The tighter the twist,
Speaker 2: the less cross stock you get.
Speaker 1: Which is exactly why a modern Cat sick cable can
Speaker 1: push gigabit speeds while an older, loosely twisted Cat five
Speaker 1: cable cannot.
Speaker 2: Exactly the physicality of it is amazing.
Speaker 1: The text also explains the difference between a straight through
Speaker 1: cable and a crossover cable. Right straight through cable is
Speaker 1: exactly what it sounds like. Pin one on one end
Speaker 1: connects to pin one on the other end. You use
Speaker 1: it to connect different types of devices, like a computer
Speaker 1: to a switch.
Speaker 2: Because the computer transmits on pin one and the switch
Speaker 2: expects to receive on pin one.
Speaker 1: Right. But if you connect two identical devices like two switches,
Speaker 1: using a straight through cable, it is like walking up
Speaker 1: to a mirror and trying to shake hands with your
Speaker 1: own reflection.
Speaker 2: That mirror analogy is spot on. If you put your
Speaker 2: right hand out, your reflection puts its right hand out,
Speaker 2: and your hands just awkwardly bump into each other.
Speaker 1: Yeah. So, if switch A transmits on pin one and
Speaker 1: switch B also transmits on pin one, the electrical signals
Speaker 1: physically collide on the wire.
Speaker 2: To fix it, you use a crossover cable, which physically
Speaker 2: crosses the transmit pins on one end over to the
Speaker 2: receive pins on the other.
Speaker 1: You are crossing your arms to shake hands of the mirror,
Speaker 1: ensuring the dat lands perfectly where it is expected.
Speaker 2: Precisely. But copper is just one medium. The true backbone
Speaker 2: of the global Internet is fiber optic cabling, which is
Speaker 2: just mine bending because.
Speaker 1: We are shooting actual lasers down tubes of glass. Yeah.
Speaker 2: By using pulses of light instead of electricity, fiber optics
Speaker 2: are completely immune to electromagnetic interference. There is zero cross stock,
Speaker 2: and the.
Speaker 1: Material highlights two distinct types, single mode and multimode. Single
Speaker 1: mode fiber has a microscopic glass core, typically around nine
Speaker 1: microns thick.
Speaker 2: Which is significantly thinner than a single strand of human hair.
Speaker 1: That's just wild.
Speaker 2: It uses a highly focused, expensive laser to shoot a
Speaker 2: concentrated beam of light straight down that tiny core. Because
Speaker 2: the light does not disperse or bounce around, it maintains
Speaker 2: its integrity over massive distances, so.
Speaker 1: Delecom companies use single mode fiber to cross oceans and
Speaker 1: connect cities exactly.
Speaker 2: Multimode fiber, conversely, has a much wider core, usually fifty microns,
Speaker 2: uses a cheaper led light source that physically bounces off
Speaker 2: the interior walls of the glass as it travels.
Speaker 1: And because the light is rickicheting off the walls, it
Speaker 1: naturally spreads out and gets fuzzy over long distances.
Speaker 2: Right, So multimode is heavily restricted to short runs like
Speaker 2: connecting different server racks within the same physical building. Single
Speaker 2: mode handles the cross country heavy lifting.
Speaker 1: Got it. There's one more crucial physical technology to cover
Speaker 1: power over Ethernet or POE.
Speaker 2: Ah yes, standards like aightoh two point three AF and
Speaker 2: a two point three APP.
Speaker 1: These allow a network switch to send both high speed
Speaker 1: data and low voltage electrical power down the exact same
Speaker 1: copper UTP cable.
Speaker 2: It's incredibly useful. Think about the logistics of outfitting a
Speaker 2: massive one hundred thousand square foot warehouse with security cameras.
Speaker 1: Right, If every camera requires a dedicated power outlet, you
Speaker 1: have to hire licensed electricians to run heavy condo it
Speaker 1: up into the rafters for every single device, which costs
Speaker 1: an absolute fortune.
Speaker 2: But with POE, you just run one cheap CAT six
Speaker 2: cable from the network switch to the camera.
Speaker 1: The switch pumps the DC power to turn the camera
Speaker 1: on and receives the four K video feedback over the
Speaker 1: exact same wire. It's a masterpiece of efficiency, it really is.
Speaker 2: So we have built the physical roads, established the intersections,
Speaker 2: and powered the devices.
Speaker 1: But none of this infrastructure means anything if the devices
Speaker 1: do not speak a common language.
Speaker 2: Which brings us to the protocols, specifically TCPIP and the
Speaker 2: DoD model, and the.
Speaker 1: History here is deeply tied to the Cold War. In
Speaker 1: the nineteen seventies, the Department of Defense funded the Arpennet project.
Speaker 2: They needed a communications network that could survive a catastrophic event.
Speaker 1: The underlying logic had to be so robust that if
Speaker 1: half the country's infrastructure was wiped out in a nuclear strike,
Speaker 1: the surviving computers could automatically route data around the crater
Speaker 1: to find a new path to the destination.
Speaker 2: So they engineered a four layer architecture known as the
Speaker 2: DoD model process application host to host or transport Internet
Speaker 2: and network access.
Speaker 1: The true brilliance of this model is its open systems
Speaker 1: approach right.
Speaker 2: Exactly Unlike proprietary tech, where every piece of hardware has
Speaker 2: come from the same vendor, TCPIP is completely agnostic at
Speaker 2: the bottom layer, so.
Speaker 1: The physical network access layer just does not care what
Speaker 1: the medium is.
Speaker 2: Right, the upper layers process the digital data exactly the
Speaker 2: same way, whether that bottom layer is a copper telephone wire,
Speaker 2: a transatlantic fiber optic glass tube, or a modern Wi
Speaker 2: Fi radio wave bouncing around your living room.
Speaker 1: And understanding that nineteen seventies layered architecture is actually the
Speaker 1: secret to troubleshooting your own home Wi Fi today, it
Speaker 1: really is.
Speaker 2: When your laptop suddenly cannot load a web page, you
Speaker 2: troubleshoot systematically, layer by layer. First, the physical network access layer,
Speaker 2: is the Wi Fi radio actually connected?
Speaker 1: Next the Internet layer, did the router assign you a
Speaker 1: valid IP address?
Speaker 2: Then up to the application layer, is the browser failing
Speaker 2: to resolve the website name? It gives you a mental
Speaker 2: map to isolate the exact point of failure.
Speaker 1: Let's zoom in on that top layer, the application layer.
Speaker 1: These are the unsung background protocols making our digital lives function.
Speaker 1: Let's start with DNS, the Domain Name system.
Speaker 2: Because computers do not understand English words, they only understand numbers,
Speaker 2: specifically IP addresses.
Speaker 1: But no one wants to type a random string of
Speaker 1: numbers into their browser to check the news. So DNS
Speaker 1: is basically the Internet's phone book exactly.
Speaker 2: It translates human readable URLs, what the networking world calls
Speaker 2: fully qualified domain names into the exact IP addresses the
Speaker 2: machines need to connect.
Speaker 1: But before your phone can even access that DNS phone book,
Speaker 1: it needs its own IP address. That's the job of DHCP,
Speaker 1: the dynamic host configuration protocol.
Speaker 2: Right when you walk into a coffee shop and your
Speaker 2: phone connects to the Wi Fi, it has no identity
Speaker 2: on that network. It cannot send a targeted message to
Speaker 2: the router to ask for an address because it does
Speaker 2: not have a return address yet, so it.
Speaker 1: Literally has to shout into the digital void. The phone
Speaker 1: sends out a massive broadcast message to the entire local network,
Speaker 1: basically disagreement. Is there a DHCP server out there that
Speaker 1: can give me an IP address?
Speaker 2: And this kicks off what is known as the door
Speaker 2: our process Discover, Offer, request, acknowledge. Your phone's shout is
Speaker 2: the discover message, and.
Speaker 1: The router hears it and replies with an offer of
Speaker 1: an available IP address.
Speaker 2: Your phone then formally requests to lock in that specific address,
Speaker 2: and the router acknowledges the lease. This four step negotiation
Speaker 2: happens in a fraction of a second.
Speaker 1: But if that DHCP server is frozen or dead, the
Speaker 1: phone panics. It realizes no one is answering the shout,
Speaker 1: so it automatically assigns itself an APAPA address automatic private
Speaker 1: IP addressing.
Speaker 2: It just pulls a random address in the one sixty
Speaker 2: nine point two five four range.
Speaker 1: Yeah, if you are ever trying to fix a broken
Speaker 1: Internet connection and you look at your computer settings and
Speaker 1: see an IP address starting with one sixty nine point
Speaker 1: twenty five four, it is a massive red flag.
Speaker 2: It instantly tells you the device is completely isolated and
Speaker 2: cannot reach the router. It is an invaluable diagnostic clue, and.
Speaker 1: The application layer also dictates how we remotely manage these devices.
Speaker 2: Yes, for decades, engineers use telnet, which is incredibly lightweight
Speaker 2: but fundamentally flawed because it sends every keystroke in clear text.
Speaker 1: So if an engineer types of password, anyone listening on
Speaker 1: the local network can intercept and read it exactly.
Speaker 2: Today, that has been entirely replaced by SSH secure shell,
Speaker 2: which encrypts the entire remote session.
Speaker 1: Now, the protocol that really caught me off guard in
Speaker 1: this section is MTP, the Network Time Protocol.
Speaker 2: Oh. Yeah, NTP is crucial.
Speaker 1: It reaches out to atomic clocks on the Internet to
Speaker 1: perfectly synchronize your device's internal clock. But honestly, in a
Speaker 1: world of deep packet inspecting firewalls and fiber optic lasers,
Speaker 1: why is simply knowing what time it is considered a
Speaker 1: mission critical function.
Speaker 2: It only seems trivial until you look at how digital
Speaker 2: security and databases function really just the time. Yeah, almost
Speaker 2: every encrypted transaction and database entry relies entirely on exact timestamps.
Speaker 2: If a financial service clock drifts out of sync by
Speaker 2: just a few seconds compared to the rest of the
Speaker 2: banking network, it might log a cash withdrawal is happening
Speaker 2: before the direct deposit that actually funded the account.
Speaker 1: Oh wow, the database logic just collapses.
Speaker 2: Furthermore, modern website security certificates are time bound. If your
Speaker 2: computer's internal clock gets reset and thinks the years twenty eighteen,
Speaker 2: your browser will reject every secure website you try to
Speaker 2: visit because it believes their modern security certificates haven't been
Speaker 2: issued yet.
Speaker 1: So milliseconds of time drift can quite literally break global networks. Okay,
Speaker 1: NTP is officially vital, very much so. So the application
Speaker 1: layer has resolved our names, checked the time, and packed
Speaker 1: our data into a digital box. Now we drop down
Speaker 1: a level to the transport layer, which has to physically
Speaker 1: ship that box across the world.
Speaker 2: And there are two competing delivery protocols here, TCP and UDP.
Speaker 2: It is the classic engineering trade off of absolute reliability
Speaker 2: versus raw speed.
Speaker 1: Let's examine TCP first. The Transmission Control Protocol.
Speaker 2: TCP is connection oriented. It refuses to send a single
Speaker 2: drop of data until it reaches out to the receiving
Speaker 2: computer and establishes a formal virtual circuit.
Speaker 1: It sequences every single packet with a specific number right yes.
Speaker 2: Checks for errors upon arrival, and rigorously demands an acknowledgment
Speaker 2: for every packet received.
Speaker 1: It's the digital equivalent of sending a highly sensitive legal
Speaker 1: contract via certified mail. You don't just drop the contract
Speaker 1: in a blue mailbox and cross your fingers. You force
Speaker 1: the recipient to sign for every single page exactly.
Speaker 2: If page four gets lost in transit, the recipient looks
Speaker 2: at the sequence numbers and says, hey, I receive pages one, two, three,
Speaker 2: and five, resend page four.
Speaker 1: So it is one hundred percent reliable. But all that checking, sequencing,
Speaker 1: and acknowledging creates massive overhead. It slows the Intel process down,
Speaker 1: and that.
Speaker 2: Heavy overhead is exactly why UDP exists. The User Datagram
Speaker 2: Protocol is connectionless. It is a thin protocol.
Speaker 1: Meaning it does not establish a virtual circuit.
Speaker 2: Right it does not sequence the packets into a specific order,
Speaker 2: and it absolutely does not ask for an acknowledge. It
Speaker 2: just takes the data and fires it at the destination
Speaker 2: as fast as the hardware will allow.
Speaker 1: It's like writing a thousand postcards and throwing them out
Speaker 1: the window of a moving train, just hoping they land
Speaker 1: in the recipient's mailbox.
Speaker 2: That's a fun way to picture it.
Speaker 1: But yeah, if twenty postcards blow away in the wind,
Speaker 1: UDP doesn't care. It just keeps throwing more postcards, which
Speaker 1: sounds terrible until you think about a live video stream
Speaker 1: or a voiceover IP phone call.
Speaker 2: Precisely, if you drop a single frame of video or
Speaker 2: a tiny fraction of a syllable during a call, you
Speaker 2: absolutely do not want the network to pause the entire
Speaker 2: live feed to go back and request that missing data, because.
Speaker 1: By the time it retrieves the dropped frame, the live
Speaker 1: moment has passed. You just want the stream to keep
Speaker 1: moving forward.
Speaker 2: So UDP is perfect for live video, but it would
Speaker 2: be disastrous for a bank transfer. Every protocol, every cable,
Speaker 2: and every router has a highly specific purpose.
Speaker 1: It is a staggering symphony of engineering. We have taken
Speaker 1: the chaotic unpredictable nature of electrical impulses and light waves
Speaker 1: layered upon them a set of logical rules so uncompromising
Speaker 1: and robust that they can seamlessly orchestrate billions of devices
Speaker 1: across the globe simultaneously.
Speaker 2: It's incredible when you step back and look at it all.
Speaker 1: We've covered an incredible amount of ground today. From the
Speaker 1: physical light shooting down a microscopic fiber optic core, bouncing
Speaker 1: through the intelligent polite intersections of ame address reading switches,
Speaker 1: past the strict local bouncers we call routers.
Speaker 2: We scaled up through hierarchical network designs and zoomed all
Speaker 2: the way into the Cold War era rules of TCPIP
Speaker 2: that ensure every packet finds its way to your screen.
Speaker 1: But here's a final thought, feedom all over. PCPIP was
Speaker 1: originally designed in the nineteen seventies. It was built to
Speaker 1: route data across physical copper telephone wires to survive a
Speaker 1: Cold War catastrophe. Today, we are rapidly moving into an
Speaker 1: era of space based satellite internet constellations, gigabit fiber, and
Speaker 1: eventually quantum computing. Will this brilliant decades old foundational logic
Speaker 1: finally need to be completely rewritten to handle the physical
Speaker 1: realities of the future. Or is the underlying architecture of
Speaker 1: the Internet truly remarkably future proof.
Speaker 2: That is a fundamental question that network engineers will be
Speaker 2: wrestling with for the next decade.
Speaker 1: Thank you so much for joining us on this deep
Speaker 1: dives into the invisible architecture of the web. Keep asking questions,
Speaker 1: keep looking beneath the frictionless surface of your screens, and
Speaker 1: we will catch you on the next one.