Week 5: Day 015 - Modern Ethernet #1

Did you think that the Ethernet sections were done? WRONG! We got another one, and this one is very important, since it describes the modern changes to Ethernet. Let's get started!

Firstly, let's talk about the 100BaseT. When we talk about companies that set standards for networks, they make a lot of money! Naturally, many will try to get people to standardize to their own patented products, but only few come through with that. So, when people wanted to upgrade 10BaseT, many potential standards came up, but again, only few were chosen. Here we have two-twisted pair Ethernet standards which succeeded. These are called 100BaseT4 and 100BaseTX. The T4 used a CAT-3 cable, while the TX used CAT-5. As a result, the 100BaseTX became the dominant 100-megabit standard in the late 90's. This caused the T4 to become extinct in the consumer market, giving people the ability of shortening the standard name to "100BaseT" which is not that much of an abbreviation haha.

To summarize the 100BaseTX(T), according to the text book, it has this to offer:
- Speed: 100 Mbps
- Signal Type: Baseband
- Distance: 100 meters between switch and node
- Node limit: No more than 1024 per hub/switch
- Topology: Star-bus topology (physical star, logical bus)
- Cable Type: CAT 5e or UTP and STP cabling w/ RJ-45 connectors

Now that we got that out of the way, let's talk about the 100BaseT. Back in the day, if you were upgrading you network from 10BaseT to 100BaseT, it was no simple task. You needed a CAT 5 cable or better, you had to replace all the NICs, and replace the hubs and switches. Obviously this is a tedious task, so people wanted to make it easier to upgrade. This was accomplished through multispeed and the "auto-sensing" of NICs and switches. Basically auto-sensing is when an NIC connects to a network for the first time, it starts discussing with the switch on what the other device's highest speed is. If the both the NIC and the switch do 100BaseT, then that's what you get, but if the switch does only 10BaseT, then that's what you're NIC will adapt to, and ultimately what you get. This all happens automatically when it auto-senses via multispeed. When you try to distinguish 100BaseT from 10BaseT it's really hard without closely looking at it. You'll have to look on the card to see the speed, there may be extra link lights which will also tell you. You could also install the card and see what your OS tells you. And to be honest, it might even be pointless to check, as all modern NIC's are multispeed, and the old singlespeed ones are extinct.

Just like the 10BaseT, this 100BaseT has a fiber-optic counterpart. This is called "100BaseFX". So once again, when it comes to big office buildings, sometimes UTP cabling won't cut it, and the type of cabling used for 100BaseFX goes further distances. Also back to the Electrical interferences, UTP is very prone to this in areas with many electrical devices and appliances, unlike fiber-optic cable. Apparently, UTP cabling is also not very secure, so if you're the government, don't use this! On a final note, this looks almost exactly like the 10BaseFL which is not surprising at all. This is kind of like how the 100BaseT looks just like the 10BaseT.

Anyways here is the textbook summary:
- Speed: 100 Mbps
- Signal Type: Baseband
- Distance: Two kilometers!!! between switch and node
- Node limit: No more than 1024 per hub/switch
- Topology: Star-bus topology (physical star, logical bus)
- Cable Type: Multimode fiber-optic cabling with ST or SC connectors.

That ends today's entry, yes I know pretty short, but the next one will be pretty big! Thanks for reading, and as always, have a good day!