When it comes to the Internet, there’s a lot of jargon flying around DSL, FTTH, ISP… it can feel like a secret code only network engineers understand. Let’s break these down in a way that actually makes sense.
DSL (Digital Subscriber Line)
DSL is a technology that transmits data over traditional telephone lines. Unlike the old dial-up, DSL lets you stay online while using the phone. It’s the classic way ISPs bring Internet to homes without laying new fiber everywhere.
ADSL (Asymmetric Digital Subscriber Line)
ADSL is a type of DSL where download speeds are higher than upload speeds. Perfect for home users because most of us download way more than we upload (Netflix, YouTube, gaming, etc.).
SDSL (Symmetric Digital Subscriber Line)
SDSL is the opposite of ADSL: download and upload speeds are the same. This is ideal for businesses or anyone running servers where uploading data is as important as downloading.
DSLAM (Digital Subscriber Line Access Multiplexer)
A DSLAM is like the traffic director at the ISP. It aggregates multiple DSL connections from users and sends them onto a high-speed backbone network. Think of it as the hub where all the neighborhood DSL lines meet before heading out to the Internet.
Fiber Optic Internet
Fiber is the modern upgrade over DSL, and it comes in different flavors:
- FTTH (Fiber to the Home): Fiber goes straight into your home. Best speeds, lowest latency.
- FTTB (Fiber to the Building): Fiber reaches the building, then internal cables distribute it to each apartment or office.
- FTTN (Fiber to the Node): Fiber reaches a neighborhood node, then copper cables complete the connection to homes. Slightly slower than FTTH.
ISP / FAI
- ISP (Internet Service Provider): The company that gives you access to the Internet. Examples: Comcast, Orange, AT\&T.
- FAI (Fournisseur d’Accès Internet): Same as ISP, but it’s the French term.
AS (Autonomous System)
An Autonomous System (AS) is a network, or a group of networks, under one administrative control, using a common routing protocol. Each AS has a unique number (ASN) and communicates with other ASes via BGP (Border Gateway Protocol). Basically, it’s like a city in the global Internet traffic map.