What is gateway?

Gateways are essential for communication between different networks or servers. As a kind of translation tool for network protocols, they ensure that the desired data can be correctly transmitted from one network to another. They are used in private and business areas.

  • Gateways translate the network protocol of a system or network by converting incoming information so that another system can understand it.
  • The communicating systems can be networks, individual computers or programs.
  • Internet routers that link IP networks and thus enable access to the Internet are also known as “default gateways”.

What is a gateway?

The English term “gateway” means “access” in German and is common in the IT sector. A gateway serves as a link between two systems or networks that use different protocols and communication services – it grants one network access to another. In general, gateways establish a connection between a source and a destination by transferring data between the two points in a meaningful and legible manner. A gateway is able to record the specific properties of the sender and receiver and use them for the transmission. These include, for example, the type of protocol, the speed of data transmission, the file formats, the addressing and the hardware used.

The so-called OSI model (Open Systems Interconnection) provides a framework for communication between different technical systems. The model defines the tasks that must be carried out for error-free communication between sender and receiver and arranges the corresponding network protocols in seven layers:

  • Layer 1: bit transmission
  • Layer 2: Backup
  • Layer 3: Mediation
  • Layer 4: Transportation
  • Layer 5: session
  • Layer 6: representation
  • Layer 7: application

Gateways are used on every shift. The way you work depends on the task being performed on each shift.

Where are gateways used?

Gateways can be found in a variety of forms, all of which serve one purpose: They are intermediaries between different systems that otherwise might not be compatible and could not communicate with each other.

So-called media gateways occur in the field of telecommunications media. There they serve as transitions between different networks that convert audio, image or video data and make it readable for the different network types. The information of the protocols as well as the direct user data are “translated”. Gateways within software, on the other hand, are connection points to specific payment gateways or a specific website.

Gateways also exist as the basis for so-called network tunnels. This includes, for example, internal company networks that authorized users can access remotely. Networks of this type are also called Virtual Private Networks (VPN), the corresponding connection points VPN gateways. External access is via the Internet.

Differentiation from a network router

The way a router works is very similar to a gateway: it receives information from the network, analyzes this data and forwards it to another network. The main difference to the gateway is that a router does not change the data itself – a gateway converts it if necessary. In addition, a gateway works on all layers of the OSI model, a router only on the third one, which is used for switching.

Routers – often also called “Default Gateway” – are primarily used to connect a home network (e.g. PC, laptop, printer) to the Internet – be it by cable or wirelessly. To do this, the Internet router links different IP networks with one another.

What does the message “502 Bad Gateway” mean?

All inquiries on the Internet work through gateways. If a particular server or website cannot be accessed, the HTTP error code “502 Bad Gateway” often appears. This means that communication between the networks or servers is not working properly. The reason for this is often on the server side, for example there may be a failure or overloading of a particular server. In this case, only the respective web host can fix the error. In rare cases, however, the connection disruption is caused by the Internet user – for example, if the PC’s firewall or Internet browser extensions block forwarding to the desired website.