Networking Basics Lesson 006: Optical Cabling

Fiber Optic Cables

Use light from LEDs or lasers to transmit data through thin strands of glass or plastic.

What is the biggest benefits to using fiber optic cables?

EMI has no effect on them, longer supported cable distances, spanning oceans, and high-speed transmission in terabits per second.

What are the biggest caveats to using fiber optic cables?

They are extremely expensive to buy and install and require expertise to install, terminate, and repair.

What are the two main category types of fiber optic cable?

Single Mode Fiber (SMF) and Multimode Fiber (MMF).

Single Mode Fiber (SMF)

Contains a narrow core (8.3-10 microns in diameter) and allows one beam of light to travel in a straight path.

What is the benefit of using a SMF cable?

Reduces dispersion and enables long distance communication, spanning several kilometers.

Where are single mode fiber cables most often used?

In infrastructure projects for neighborhood Internet service and long-haul communication lines.

Multimode Fiber (MMF)

Contains a wide core (50-100 microns in diameter) and allows multiple beams of light to bounce and refract within a fiber optic cable.

What is the ideal maximum length of a MMF calble?

Around two kilometers in length, or 1.2 miles.

Where are MMF cables commonly used?

As patch cable connections between routers, switches, and servers, and within data servers.

What is the benefit of using MMF cables?

They are cheaper and easier to produce than SMF due to its larger core size.

What is the caveat to using MMF cables?

Can only be used for relatively shorter distances due to signal dispersion, compared to SMF cables.

How does one tell the difference between a SMF cable and a MMF cable?

SMF cables usually have a yellow sheath, MMF cables usually have an aqua blue or orange sheath.

What type of fiber optic cable needs to be used for covering longer distances?

An SMF cable.

What are the four main connector types used for terminating fiber optic cables?

Subscriber Connector (SC), Straight Tip (ST) Connector, Lucent Connector (LC), and Mechanical Transfer Registered Jack (MTRJ).

Which fiber optic cable connector is most popular and most commonly used?

Subscriber Connector (SC).

What makes SCs popular?

They are low cost, durable, and easy to install.

Subscriber Connector (SC)

A type of fiber optic cable connector that has two cables bundled together.

What are the two cables in a SC used for?

One for receiving data and one for sending data.

How is a SC installed?

Stick it in and push till you hear a click.

What a SCs primarily used for?

Telecommunications and data communication networks, i.e. Internet, TV, and phone services.

Straight Tip (ST) Connector

Older and durable style of fiber optic connector, that requires two cables in order to send and receive data from a device.

What is the benefit of using a ST connector?

It's relatively low cost.

How is a ST connector plugged in?

By sticking it into the proper port and twisting it to the right to tighten.

What are ST connectors primarily used for?

Connecting equipment like switches, routers, and patch panels in LANs, data centers and telecom networks.

Lucent Connector (LC)

A newer and smaller type of fiber optic cable connector that usually has the transmit and receive cables married together or can be locked into each other.

What are LCs mainly used for?

In high density areas like data centers, telecommunication networks and enterprise networks.

Mechanical Transfer Registered Jack (MTRJ) Connector

A popular and widely used fiber optic cable connector with a smaller form factor, with the transmitting and receiving pins terminated inside a single plastic connector.

What is the main benefit to using a MTRJ Connector?

Because of its compact form factor, the same amount of these can fit into the same chassis size of a regular RJ45 copper switch.

What are the MTRJs mainly used for?

Compact, duplex connections in fiber optic networks.

What type of network is ideal to use MTRJs on?

LANs.

What are MTRJs primarily used for?

In data centers and telecommunications to connect devices like switches, router, and servers where space is limited and high port density is needed.

What is the most common limiting factor in network speed when using fiber optic cables?

The speed of network switches and routers.