• Fabian Sinner
  • February 20, 2024

Table of content


    A backbone on the Internet refers to the central network of high-speed connections and routers that connect the various parts of the Internet. Metaphorically speaking, it is the the “backbone” that is responsible for data traffic between distant locations.

    What exactly is a backbone?

    Backbones connect local and regional networks (such as the networks of Internet service providers) with national and international networks, enabling global data traffic. High-speed lines are used for data transmission (e.g., fiber optic cables), which can transport large amounts of data quickly over long distances. Satellite-based radio links are also used.

    Backbones consist of a series of central nodes and main distribution centers, which are usually located in large cities or other important traffic hubs. Backbones are often redundant, meaning that they have multiple parallel paths to increase reliability and minimize outages. If one part of the backbone fails, traffic can be rerouted thanks to the built-in redundancy.

    Backbone operators are usually large telecommunications companies (e.g., Deutsche Telekom/T-Mobile US) or specialized companies that maintain and expand the infrastructure. Submarine and transcontinental cables are an important part of backbones because they connect continents and countries. Internet backbones are essential for the proper functioning of the Internet, as they form the basis for data traffic between different parts of the network.

    The technical functionality of backbones

    The technical functioning of Internet backbones is based on a combination of hardware, software, and network protocols.

    • High-speed lines: Backbones consist of high-speed data transmission lines, usually fiber optic cables. These cables use light to transmit data at extremely high speeds over long distances.
    • Routers and switches: Powerful routers and switches are used in the backbone network. Routers forward data packets based on their destination address. They are crucial for determining the most efficient path for data through the complex network. Switches connect devices within a local network and forward data based on the MAC address.
    • Network protocols: The Internet uses the TCP/IP protocol (Transmission Control Protocol/Internet Protocol) to control data traffic. IP is responsible for addressing and routing data packets, while TCP ensures reliable transmission by acknowledging the arrival of packets and resending any lost or damaged packets.
    • Peering and transit: Backbone networks are connected to each other via peering agreements and transit connections. With peering, two networks exchange data directly without paying for it, while with transit, one network allows another to use its connections for a fee.
    • Network nodes (points of presence, PoPs): These are physical access points where different networks connect to the backbone. Here, the transitions between different types of networks often take place; for example, from local networks to national and international backbones.
    • Management: Backbone networks must be continuously monitored and maintained to ensure performance, security, and reliability. This requires advanced network management systems.
    • Redundancy: To avoid failures, backbones are often designed redundantly, with multiple paths between two points. If one connection fails, traffic can be automatically rerouted.

    Why are backbones so important?

    They enable global networking by connecting local and regional networks. Without backbones, it would not be possible for data to be transmitted quickly and reliably across continents and oceans. Importantly, they are designed to handle an enormous amount of data traffic through high-speed fiber optic cables and other advanced technologies, meaning they can transport large amounts of data efficiently across massive distances.

    Through redundant connection paths and systems, backbones ensure that the Internet remains functional even in the event of disruptions such as cable damage or system failures. They enable data traffic to be rerouted quickly in order to minimize downtimes. Backbones are designed to scale with the ever-growing levels of data traffic and increasing demands of the Internet. This is crucial to keep pace with the increasing number of users, devices, and services.

    From simple web browsing and streaming services to complex cloud applications and the Internet of Things (IoT), backbones enable the wide range of services and applications we use every day. They are the basis for numerous economic activities and are crucial for modern communication. Businesses, governments and individuals depend on a reliable and efficient Internet. The existence and continued development of Internet backbones enables technological innovation and promotes growth in many areas, from business to education.

    In short, Internet backbones are the foundation on which the modern, global Internet is built. They are critical to its performance, reliability and expandability.

    Different backbone areas

    Backbone structures can be found in networks of all sizes, i.e., in local, regional and supra-regional networks as well as in the entire Internet. There are so-called Internet backbones, but also backbones in wide area networks (WAN) or local area networks (LAN).

    What are collapsed backbones and distributed backbones?

    Collapsed backbones and distributed backbones mainly play a role in LAN areas when networking floors or buildings as part of corporate networks.

    The difference between collapsed backbones and distributed backbones lies in the architecture and the way in which network connections and data traffic are organized and managed. Both terms refer to different approaches in the design of network backbones.

    A collapsed backbone is a network architecture in which all connections of a network converge in a single central router or switch. This device acts as the central hub for the entire network. A distributed backbone is a network architecture in which multiple backbone connections are distributed across different devices and locations.

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