Did you know that HTTP is almost universally used for communication between edge/cloud/fog services?

What is the http protocol?

The HTTP protocol, as its full name implies (Hypertext Transfer Protocol), has been designed for clients to access resources in web servers. However, over the years it has gained popularity also in other areas, such as service oriented architectures, remote procedure calls, and REST Application Programming Interfaces (APIs).

The HTTP does not natively support confidentiality and authentication, which are key in virtually all use cases of practical interest in any domain. However, these features can be enabled by intermediate layers such as the Secure Socket Layers (SSL, now obsolete) and Transport Layer Security (TLS), which we all use every day when accessing a website starting with “”https”” rather than the good old prefix “”http””. The HTTP is a layer 5 (a.k.a. session) protocol and it uses underneath TCP as a transport layer, e.g., for guaranteed delivery, flow control, and congestion avoidance.

The combined use of TCP and TLS makes the HTTP rather cumbersome on the uptake: before the first byte can be transferred from the client to the server, there are quite a few exchanges that must occur, each requiring a Round Trip Trip (RTT), which is the time it takes for a message to go from a client to the server and back to the client. When we are browsing the web, we usually do not notice such an additional delay, because it is much smaller than the time it takes to load the page, which possibly includes a lot of heavy images and videos.

Why does this matter for MARVEL framework?

In many smart city applications, such as urban sensing for real-time analytics, which we address in the project H2020 MARVEL, the message to be transmitted can be very small (e.g., the number of people estimated by a camera in a square or a car plate number), hence it becomes highly inefficient to spend so many RTTs just for such a tiny piece of information to be conveyed.

At the Institute of Informatics and Telematics of CNR we are studying solutions to reduce significantly the communication overhead of HTTP/TCP, based on the use of the QUIC protocol, which has been developed originally by Google a few years ago, but has been standardised earlier this year as IETF RFC 9000. QUIC supports natively confidentiality and authentication and it can cut down the start-up latency to 1 RTT (even 0 RTTs, actually!), which can be highly beneficial to edge/fog applications in the smart city that generate a lot of small messages.

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Blog series is organized by:  Claudio Cicconetti from the CNR team

Key Facts

  • Project Coordinator: Dr. Sotiris Ioannidis
  • Institution: Foundation for Research and Technology Hellas (FORTH)
  • E-mail: marvel-info@marvel-project.eu 
  • Start: 01.01.2021
  • Duration: 36 months
  • Participating Organisations: 17
  • Number of countries: 12

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This project has received funding from the European Union’s Horizon 2020 Research and Innovation program under grant agreement No 957337. The website reflects only the view of the author(s) and the Commission is not responsible for any use that may be made of the information it contains.