Backbone Networks: Types & Uses – Video & Lesson Transcript | Study.com

Serial Backbone

The serial backbone consists of two or more connected devices or nodes linked to each other via a single cable in series that connects to an extension to the network. It’s the most simple of all backbone architecture but is rarely used for enterprise-level network topologies because of its high susceptibility to faults and system downtime. If a link between routers becomes faulty, the whole network may get disrupted, as there are no alternate data transmission routes. Therefore, this type is only used in small network setups.

Figure 1 shows an example of a serial backbone:

Figure 1: Serial Backbone Network

Distributed Backbone

The distributed backbone network comprises a hierarchical formation of devices that are adaptable to multiple connectivity. For example, if multiple devices are connected to switches, these form the intermediary devices connecting to the backbone router and gateway devices.

The distributed backbone network, unlike the serial backbone network, is well suited for enterprise-wide connectivity. Expanding and troubleshooting the network is simple, as layers of the network are easily added and managed.

An example is shown in Figure 2:

Figure 2: Distributed Backbone Network

Collapsed Backbone

The collapsed backbone network makes use of a single, high specification router that serves as the central connection supporting the rest of the network. As the backbone, it’s characterized by high computational power to adequately handle the traffic from various networks. With this setup, the entire network is dependent on this single router, making the network extremely vulnerable. If the router goes down for any reason, so does the entire network. This type of backbone topology is mainly applicable in situations where two different types of sub networks need to be connected and managed effectively.

A collapsed backbone is shown in Figure 3.

Figure 3: Collapsed Backbone Network

Parallel Backbone

Parallel backbone networks employ a system of replicated connections to the backbone infrastructure. In this system, nodes and switches are implemented with duplicate concurrent connections to the high-level backbone routers. Not all nodes need to have the parallel connection, but strategic points of the network could be designed as such.

Because the connections function concurrently, network availability at all times is ensured. This setup also ensures high network speeds, robustness, and high fault tolerance. With this replicated setup, implementation costs get expensive with the increased cabling. The parallel backbone is a variation of the collapsed backbone infrastructure used to connect and managed different types of sub networks effectively.

A parallel backbone is shown in Figure 4.

Lesson Summary

Backbone networks are networks designed with high capacity connectivity infrastructure that form the main link, or backbone, connecting the different parts of the network. The network consists of various LANs, WANs, and sub networks. The backbone normally comprises of high specification routers and gateways.

Different types of backbone networks include:

• The serial backbone: uses two or more connected devices linked to each other by hubs. It’s simple and easy to implement but is only used in small network setups because of its high susceptibility to faults and system downtime.
• The distributed backbone: spans a larger network with multiple sub networks connected.
• The collapsed backbone: makes use of a single, high specification router that serves as the central connection supporting the rest of the network.
• The parallel backbone: employs a system of replicated connections to the backbone infrastructure. It’s a variation of the collapsed backbone, but offers higher fault tolerance capabilities.