Tech Explained: the Glossary
We’ve created a new series of blogs and resources, entitled “Techsplanations,” with the goal of providing folks with a better understanding of the technologies that shape our everyday lives. Please utilize this glossary as a reference for the key terms and concepts we mention.
If you want to make informed decisions about your interactions with technology or to engage with policy and lawmakers at a more granular level, this series is for you. (And if you already have a good grasp on the topics presented, consider using this series as an educational entry point for your friends and relatives.)
Access network – The network that connects you to the rest of the internet. This may be an ISP or mobile carrier network. Unless you are a network operator, access networks are the only way to connect to the internet, which puts access providers in a strategically powerful position since they control whether you connect, whether the rest of the internet can connect with you, and the conditions of that connection.
Backbone network – Also called “core networks,” they are the long-distance, heavy haulers of the internet, carrying bulk traffic between other networks.
Broadband Internet Access Service (BIAS) – The service that uses an access network to provide the ability to transmit and receive data from all or substantially all endpoints of the internet. This term is used by the FCC to describe the mass market high-speed internet access offerings of ISPs, and the internet access that most consumers receive at home can be classified as BIAS. BIAS providers use their position as gatekeepers to monetize access in both directions (from their network to the internet and from the internet to their network).
Caching – The act of storing some popular content within the local network infrastructure. Caching improves network efficiency, reduces interconnection load, and may improve the user’s Quality of Experience. Caching is one service offered by Content Delivery Networks. May also be used in noun form, as in, “This content can be found in a cache on the server.”
Content Delivery Network (CDN) – A network, integrated with or connected to an access provider’s network, that enables more efficient delivery of edge provider content by storing it in servers that are geographically closer to users. Although some companies build and operate CDNs to deliver their own content, other providers offer CDN service for any edge provider wishing to distribute and store content closer to end users. CDN traffic must still cross the access provider’s network subject to their traffic management policies.
Data caps – A limitation on the volume of data a subscriber may transmit and receive. Once a user reaches their data cap, providers frequently charge them added fees for additional data use. Pricing network usage based on data volume is one method of monetizing network access, even though the costs associated with data transmission are extremely low compared to other network costs, such as infrastructure deployment and equipment upgrades.
Domain Name System (DNS) – The system that connects domain name addresses (for example, www.cdt.org) to IP addresses (for example, 104.20.10.17), like the phone book for the web.
Data fingerprinting – Identifying unique patterns in data from online environments (and its metadata) and associating those patterns with individual people, devices, and/or accounts.
Edge provider – Located at the edge of a network, they offer content or services online. Search engines, streaming video services, and social media platforms are all prominent examples of edge providers. While edge providers are commonly thought of as companies, individual users can also be edge providers. Some edge providers may be affiliates of access providers, which creates an incentive to favor their traffic over other edge providers.
Encryption – Encoding information so that only authorized parties can read and process it. If the right encoding/math is used, only those with the correct key can decrypt the information into a readable form.
End point – Individual nodes where networks terminate. In a hub-and-spoke network, the outer ends of the spokes are endpoints. Your connection to an access network represents an endpoint of the access network, while each device you connect to your home LAN represents and endpoint of the LAN.
HTTPS (HTTP secure) – An encrypted version of a common web communications protocol. HTTPS helps to protect the privacy of web traffic and helps secure it against attacks.
Hypertext – Text linked to other text. Links can join separate parts of the web and are used to integrate various information sources, such as web pages, pop-ups, audio or video files, and more.
Interconnection – The connections between networks. In most cases, this refers to the connections an access network shares with other networks. Interconnection points between networks give network operators the ability to control data flows between their network and others.
Internet – A network of interconnected computer networks spanning the globe and sharing common protocols; the networks that make up the internet can roughly be broken down into access providers, backbone providers, and edge providers. The internet provides the physical infrastructure over which web applications, services, and content travel between endpoints.
Internet Exchange Point (IXP) – A data center connecting two or more networks. Many traffic routing decisions are made at IXPs. IXPs are also logical locations for CDN servers.
Internet Protocol (IP) address – Like phone numbers for the internet. IP addresses represent unique endpoints of the internet, however, your network operator may change the IP address assigned to your connection from time to time.
Internet Protocol (IP) packet – The basic unit of traffic on the internet. Packets are limited in size and labelled with layers of routing and processing information.
Internet Service Provider (ISP) – The network operator that provides your access to the internet. They deliver IP packets between your IP address and the other parts of the internet to which you connect.
Latency – The time, measured in milliseconds (ms), it takes for a packet to travel from source to destination.
Local Area Network (LAN) – Exactly what it sounds like. In many cases, this is the wireless network your devices connect to at home or in the coffee shop.
Metadata – Information describing the qualities of data, how much there is, where it came from, where it’s going, etc. Although metadata does not include the actual content of messages, it can provide a detailed picture of your life when collected in bulk. For example, metadata can reveal your personal relationships, medical conditions, and sexual orientation.
Modem – At home, this is the first box that connects to the wire connecting you to the access network. The modem translates digital signals into whatever signal is appropriate for the kind of wire you have, and also translates signals from that wire into the digital signals necessary for your in-home LAN.
Network Address Translation (NAT) – A task performed by routers to sort and deliver streams of information to and from connected devices. The router translates the public IP address on packets it receives from the internet into the private addresses it assigns to your computer, phone, printer, etc. It also translates addresses in the other direction (private to public).
Net neutrality – The idea that network operators should not discriminate against any network traffic based on source, destination, protocol, content, application, or device.
Network traffic management – Practices network operators may engage in to improve the efficiency and security of their networks; most net neutrality regulations allow for reasonable network management, including allowances for specialized services that may require a specific Quality of Service.
Non-BIAS/specialized services – Anything that is not internet access (BIAS) and is not used as a substitute for internet access. These are sometimes called “specialized services” because they serve a narrow set of purposes, such as telemedicine or autonomous vehicle communication, and may require a different Quality of Service than standard internet access. These services were explicitly exempted from the scope of the 2015 Open Internet Order.
Open Internet – The idea that internet users should be able to connect any non-harmful device to the network of their choice, choose among the lawful applications, services, and content they wish, without discrimination by network operators, edge providers, or equipment manufacturers.
Packet headers – These are a bit like shipping labels. They contain information about the sender, receiver, routing, sequencing, and size of the packet (as well as some other info). This kind of information is sometimes called metadata.
Paid prioritization – A form of traffic management in which edge providers or users pay access providers to transmit some traffic before others, which necessarily makes some traffic faster and some slower. Paid prioritization uses Quality of Experience to influence users’ choices among edge providers.
Protocol – A standardized set of shared rules and conventions for… anything, but in this context, for structuring the information in online transmissions.
Quality of Experience (QoE) – The user’s perception of the speed and functionality of applications accessed over the internet; QoE reflects whether, or how well an application “works” at the user’s endpoint.
Quality of Service (QoS) – The technical parameters of an internet connection; QoS metrics include bit rate (bits per second), latency (time delay between sending and receiving packets), packet loss (number of packets not delivered), and jitter (variations in packet latency).
Router – Usually, the second box in your home (some routers may be integrated into the same box as the modem). The router keeps track of which devices are connected to the LAN and which data streams go to each. A router may use wired or wireless connections between itself and your devices. We call the wireless connection “Wi-Fi”.
Server – A computer on one end of a client-server relationship. Clients ask the server for files, the server… serves them.
Throttling – The act of slowing down network traffic. Sometimes used to manage network usage during high traffic intervals, throttling can also be done to disadvantage or deter certain kinds or sources of traffic.
Uniform Resource Locator (URL) – All that stuff after the domain name in your browser’s address bar (for example, cdt.org/this_is_the_URL), this is how the server knows which files you want. URLs are like addresses for web files.
Virtual Private Network (VPN) – A non-physical network that creates more privacy and security for its users by disguising their actual IP addresses and encrypting their traffic.
Wi-Fi – The trademark name of a wireless signal technology commonly used for short range connections to LANs.
World Wide Web (www or web) – The space containing the information with which users interact over the internet; the Web uses Uniform Resource Locators (URLs) and hyper-text programming as standards to promote universal functionality and interface between various sources. Many think of the Web and the internet as the same thing, but the web is a set of non-physical spaces that communicate via the internet.
Zero rating – The act of not counting certain data against a set limit. Zero rating can only occur where data caps are in place. Zero rating uses price to influence users’ choices among edge providers, but does not affect transmission speed.
