Internet service providers, internet connections types & data transfer technologies used on internet
Introduction to Internet Service Provider
Internet service provider or ISP is a company that provides internet connections to individuals or organizations for accessing the internet. Many phone companies, cable companies, satellite companies, and public or private companies work as ISP. Without ISPs, the internet cannot be accessed. ISPs may be commercial or nonprofit in nature.
How the concept of ISPs started and the establishment of the first commercial ISP
The internet in the beginning was just a closed network between the government research laboratories and a few universities and colleges. The employees of these institutions had access to the internet at their workplace, but they also wanted internet access at their homes and elsewhere for ease of work and research purposes. So, the ISPs came into being to provide internet access to those employees and faculty members at earlier and later for the general public also. It is said that the first commercial ISP company was “The World” made in Brookline, Massachusetts.
Three Tiers of Internet Service Providers and Data Transmission through them
Today, the internet is the most accessible thing and a global network of networks. The internet network is divided into three layers or levels at large called the 3 Tiers of ISPs and named Tier 1, Tier 2, and Tier 3. Internet consumers or customers (individuals and businesses) pay their ISPs for accessing the internet. This cascades multiple times until the transmission reaches the Tier 1 carrier.
In Which Tier Internet Service Providers are Categorised
ISP organizations connect with each other in a variety of ways which include IP transit, peering, dedicated internet access, and mass-market broadband access. The agreements and arrangements between the ISPs (for connecting and exchanging the user traffic) decide in which tier they are categorized.
Tier-1 ISP Network
A Tier 1 internet service provider is one that uses unpaid peering only to connect the Internet. Tier-1 networks own enough of the physical network lines and carry most of the traffic themselves. They negotiate with other Tier-1 networks to get free access to their networks, and vice-versa. Tier 1 ISPs can reach every other network on the internet without paying or purchasing for the IP transit (a service where an internet service provider allows traffic to travel through their network to its destination.) There are only about a dozen Tier-1 providers in the world. The world's renowned Tier-1 ISPs include CenturyLink, Verizon, AT&T, Sprint, Cogent, Global Telecom and Technology (GTT), Telia Carrier, NTT Communications, Tata Communications, and Telecom Italia Sparkle. Tier-1 ISPs are the core of the Internet and considered as the Internet backbone (the world's largest networks peered together into a seamless single network).
Tier-2 ISP Network
Tier-2 networks are the most common internet service providers. They peer with other comparably sized Tier-2 networks or buy IP transit from Tier-1 providers. Tier-2 networks focus on the regional consumer and commercial internet access and don’t have enough traffic to be considered peers of the Tier 1 providers. Main Tier-2 Carriers include Cox Communications, Comcast, Virgin Media, CTS Telecom, Vodafone, and British Telecom.
Tier-3 ISP Network
Tier-3 internet service providers are small, typically local and connect consumers to the internet exclusively by purchasing IP transit from Tier-2 ISPs or directly from Tier-1 providers. Tier-3 carriers strictly purchase IP transit and are the last mile providers who connect the individual consumers to the internet. They serve only the internet connections leading to the homes or offices of their consumers or customers.
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| 3 Tiers of internet |
Inter-connectivity of ISPs is a Complex
ISPs are interconnected to one another and with an upstream ISP at network access points. However, the situation is more complex than simply a single connection established to an upstream ISP. Some ISPs may have thousands of PoPs (point of presence or access points) and may comprise of physical location housing servers, routers, ATM switches, and analog or digital call aggregators, etc. Multiple PoPs may have separate connection types to an upstream ISP, and it is difficult to determine whether a network is paying for peering or transit as these business agreements are rarely public information. Many public ISPs, Business organizations, schools, colleges, Research and Educational institutions, Financial institutions, and other entities purchase IP transit and almost 4.5 billion people use the internet across the globe through these 3 layers of ISPs.
Internet connection types & data transfer technologies for accessing the internet
Tier-3 ISPs at local and regional levels provide different types of internet connections for the general public leading to their homes or offices which can include a Dial-up Connection, an ISDN connection, a DSL connection, Cable TV Internet, Satellite Internet, or a Wireless Internet Connection. A brief introduction to these connection types and data transfer technologies used in there is given below:
1- Dial-up Connection
A Dial-up connection uses the ordinary telephone lines and the PSTN (Public Switched Telephone Network- a collection or aggregate of the world's interconnected circuit-switched telephone networks providing infrastructure and services for public telecommunications). For connecting or accessing the internet through this method you need a dial-up modem with a communication program installed on your PC. The program instructs the modem to dial a specific number that is given by your ISP. When you make the call, your ISP opens the internet line for you, and your modem can send and receive internet data. But in this type of internet connection, you have the same line for the telephone as well as for the internet. So, at a time only one task can take place either you can run the internet, or you can talk on the telephone. This is the main disadvantage of a Dial-up connection. A dial-up modem connection can give you a data transit speed up to 56 kbit/s.
The following protocols are used in a dial-up connection for data to flow:
- Serial Line Internet Protocol (SLIP)
- Point to Point Protocol (PPP)
2- ISDN Connection
ISDN is the acronym of “Integrated Services Digital Network". It is a telephone system network, integrating the high-quality digital transmission of data and voice over the ordinary phone lines and ensuring a much better data transmission. An ISDN connection offers a faster upstream/downstream (about 128 kbit/s) than that of a standard 56 kbit/s modem. PCs are connected to an ISDN terminal adaptor, which converts the voice data (analog) into a standard ISDN format and transmits over the digital network with better quality and at a higher speed. Tow techniques are used to deliver ISDN services:
- Basic Rate Interface (BRI)
- Primary Rate Interface (PRI)
3- DSL Connection
DSL stands for the Digital Subscriber Line, a form of a broadband connection in which the bandwidth is controlled by your ISP. Bandwidth is the amount of data that can be sent and received through an internet connection in a specific time period. DSL and ISDN work over the same digital network, but the main difference is that in an ISDN connection you must dial out to access the internet as you do in a dial-up connection. While a DSL connection does not require you to dial out for accessing the internet because the digital line subscribed by you has already internet access available on it. So don't need to call out for this purpose. DSL modem not only converts the analog signals (the human voice) into digital signals (like in ISDN connection) but also filters the voice and internet data when sent and received. Therefore, you can use the internet and talk on the telephone at the same time. Seems an Upedified connection from the last one 😊 Following are the several versions of DSL techniques used today;
Asymmetric DSL or ADSL
Download speed is faster than the upload speed and mostly used at homes.
Symmetric DSL or SDSL
Download and upload speed are equal. Typically used at businesses.
High bit-rate DSL or HDSL
High-speed digital subscriber line (HDSL) offers 1.5 Mbit/s of digital bandwidth in both (symmetric) directions over common (copper) phone lines, up to 20.00 feet without using repeaters.
Very high bitrate DSL (VDSL)
It is the fastest form of the DSL with two versions available VDSL1 and VDSL2. VDSL1 offers to speed up to 52 Mbit/s downstream and 16 Mbit/s upstream over a single flat untwisted or twisted pair of copper wires. This connection can support a high-definition television stream, as well as telephone services (voice over IP) and general Internet access, over a single connection at the same time. VDSL2 (second generation) provides data rates exceeding 100 Mbit/s simultaneously in both (upstream and downstream) directions.
4- Cable TV Internet Connection
Cable TV Internet connection is provided through the Cable TV lines. It uses coaxial cables which can transfer the data at a much higher speed than common telephone lines. A cable modem is used in this service which is provided by the cable operator and comprises two types of connections: one for the internet service and the other for Cable TV signals. Since Cable TV internet connections share a set amount of bandwidth with a group of customers, therefore, the data transfer rate also varies and depends on the number of customers using the internet at the same time.
5- Optic Fiber Connection
This type of connection provides the fastest download and upload speed, up to 1000 Mb/s. This connection type uses optic fiber cables. “Fiber” refers to the thin glass wires slightly thicker than that of a human hair inside a larger protective cable and “Optic” refers to the way the data is transferred through these fibers i.e. in the form of light signals. In other types of internet connections data travels in electrical form and signals get weaker and weaker at a larger distance but in fiber optic cable, signals travel in the form of light and can travel up to much longer distances without any loss because of the high speed of light. The fiber cable is more expensive than DSL cable and TV cable.
6- Ethernet Connection
Another Internet access providing connection worth mentioning is the Ethernet - the most widespread wired LAN (local area network) technology, also used in wireless LANs. The Ethernet technology may ensure various speed levels and can thus be divided into several types:
- Regular Ethernet (up to 10 Mbits/s)
- Fast Ethernet (up to 100 Mbits/s)
- Gigabit Ethernet (up to 1 Gbit/s)
- 10-Gbit Ethernet (up to 10 Gbits/s)
7- Wireless Internet Connections
Wireless Internet Connections use Radio Frequency bands for connecting and accessing the internet. The wireless network is built with the help of several devices and hardware components like wireless access points or routers, user devices (mobile phones, tablets, laptops, or PCs) equipped with the WiFi technology adapters or Bluetooth devices or the hotspot technology along with the Wireless Application Protocol Application. WAP is the universal standard for wireless communications used in wireless internet connections. Wireless Internet can also be accessed through Wi-Fi technology which is based on the IEEE 802.11 standards and allows the electronic devices to connect to the internet. The Bluetooth wireless technology makes use of the short-wavelength radio waves and helps to create a personal area network (PAN) and the hotspot technology is relatively similar to Wi-Fi and provides Internet access via WLAN in a specific surrounding area.
1- Satellite Internet Connection
Satellite Internet connections use radio waves (microwave) for Internet connectivity and offer high data speeds. The connection includes
- A geostationary communication satellite orbiting directly over the equator.
- The ground stations are known as the (Earth Station, teleport, or hub) that relay Internet data to and from the satellite.
- A small antenna at the subscriber’s (user) location with a transceiver.
- A satellite modem which links the user's device (PC or router) with the transceiver.
- The satellite modem that modulates (input bitstream and output radio waves) and demodulates (input radio waves and output bitstream).
- And a centralized network operations center (NOC) for monitoring the entire system.
The satellite internet connection can be a;
One-way connection
Here, we can download the data only but if we want to upload, we need separate dialup access through the ISP over the telephone line
Two-way connection
Here, we can download and upload the data by the satellite, and it does not require any dialup connection.
2- Cellular Internet Connection
For a cellular Internet connection, we need a wireless application protocol (WAP)-enabled cell phone/mobile phone or tablet and a cellular internet/telephone service provider like AT&T, Verizon, Vodafone, China Mobile, Telenor or Mobilink, etc. The built-in antenna that exists in cell phones is used to send packets of digital information back and forth to cell-phone towers via radio waves.
In cellular internet connections either you can make a call from your phone or you can use the internet at a single time just like in the dial-up or ISDN connections, but speed is much higher and depends upon the signal strength which is represented by 2G, 3G, and 4G, etc. on the mobile/cell phone devices. Mobile communication has become more popular in the last few years because of the fast reforms in mobile and telecommunication technology. Following are the data speeds offered by mobile or cellular internet technology:
- 2G- (up to 64 kbit/s)
- 3G- (up to 2 Mbit/s)
- 3G-HSPA+ (up to 8 Mbit/s)
- 4G- (up to 20 Mbit/s)
- 4G-LTE (up to 50 Mbit/s)
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