Greetings all,
Back at it and not wasting time at all. I mean eh, it is 2024 right?! Goals were drafted and now the skill must be crafted. In the prior post, I spoke a bit about the world of networking and the basics. Things such as switches and routers were discussed as well as type of networks. Now I go a bit more into the interfaces and cable side of things. Yes, many would say to skip this part, but in my case I want to be a master of the field cybersecurity. I also have a background in electronics so a bit of this is a review well needed. Well, let's not wait and get into more of the notes surrounding networking. Specifically Ethernet and Fiber-optic cable will be reviewed with much in addition. Ok... I'll hush. LOL.
What are bits and bytes?
Bit:
- A value represented by 0 and 1. When communicating over copper cable, the data is sent is interpreted by the receive device using 0 or 1.
Byte:
- A series of 8 bits. 8 bits = 1 Byte.
Remember, speed is measured by bits per second. Kbps, Mbps, Gbps, etc. Never bytes per second.
- 1 Kb = 1,000 bits
- 1 Mb = 1,000,000 bits
- 1 Gb = 1,000,000,000 bits
- 1 Tb = 1,000,000,000,000 bits
What is Ethernet?
- A collection of network protocols and standards.
What is RJ-45?
- RJ-45:( Registered Jack- 45 )ie: Ethernet Connection
What are Ethernet Standards?
IEEE 802.3 standard in 1983. (Institute of Electrical and Electronics Engineers)
ie: 10-BASE-T, 100BASE-T, 1000BASE-T, 10GBASE-T)
Be sure to look up the standards listed above.
Listed in the standards are the following:
- Speed
- Common Name
- IEEE Standard
- Informal Name
- Max Length
What are UTP Cables?
(ie: Cat 6 cable )
- UnShielded Twisted Pair (No metallic shield which it vulnerable to electrical interference)
- The Twist protects against EMI (Electromagnetic Interference)
- Lower cost than fiber-optic
- Shorter max than fiber-optic (up to 100 meters)
- RJ45 ports usd with UTP are cheaper than SFP ports.
- Emit (leak) a faint signal outside of the cable which can give security risks.
What are Fiber Optic Cable?
- Sends light over glass fibers having one connection to send and one connection to receive.
Two Types of Fiber-Optic Cable are below:
Single-mode Fiber Optic Cables:
- core diameter is narrower
- light enters at a single angle mode from a laser based transmitter.
- allows longer cables than both UTP and multimode fiber.
more expensive than multimode fiber (due to more expensive laser-based SFP transmitters)
They use separate cable to send and receive connections
- fiberglass core
- cladding that reflects light
- a protective buffer
- the outer jacket of the cable.
Multi-mode Fiber Optic Cables (Cheaper than Single Mode):
- core diameter is wider than single-mode fiber
- allows multiple angles (modes) of light waves to enter the fiberglass core.
- allows longer cables than UTP, but shorter cables than single-mode fiber.
- cheaper than single-mode fiber due to cheaper LED-based SFP transmitters.
- Does NOT emit any signal outside of the cable (=no sec risk)
What is a SFP Transceiver?
- (Small form-factor pluggable): Connect a fiber optic cable to them.
Resources:
What are Ethernet Standards and Protocols?
Straight-Through vs Crossover Cable