New MS Open Tech Prototype of the HTTP/2.0 initial draft in an Apache HTTP server module

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We continue to see good momentum within the HTTP/2.0 Working Group (IETF 85 meeting) toward identifying suitable technical answers for the seven key areas of discussion, which we had identified back in August, including an update to the HTTP/2.0 Flow Control Principles draft, which Microsoft co-authored with Google and Ericsson.

Through our continuing support of the HTTP/2.0 standardization through code, we have made some updates to our prototypes and just posted them on HTML5 Labs. We have moved from the Node.js implementation used server-side by our earlier prototypes to a modified implementation of an existing Apache module for which we are making available in the associated patch.

In this latest iteration, we have made three changes in particular to advance discussions on the HTTP/2.0 initial draft and thinking around interoperable implementations:

Negotiation: we have improved upon our initial implementation of the protocol upgrade that we released last month, supporting the scenario where the server does not accept a protocol upgrade.

Flow Control: our prototype uses an infinite Window Update size that is effectively the simplest possible implementation and can be expected to be chosen for many real-world deployments, e.g. by specialized devices for the “Internet of things.”

Server push: we have implemented a behavior on the client that resets connections upon receipt of unrequested data from the server. This is particularly important where push might be especially unwelcome on mobile/low bandwidth connections.

This iteration continues to demonstrate our ongoing commitment to the HTTP/2.0 standardization process. Throughout this journey, we have honored the tenets that we stated in earlier updates:

  • Maintain existing HTTP semantics.
  • Maintain the integrity of the layered architecture.
  • Use existing standards when available to make it easy for the protocol to work with the current Web infrastructure.
  • Be broadly applicable and flexible by keeping the client in control of content.
  • Account for the needs of modern mobile clients, including power efficiency, support for HTTP-based applications, and connectivity through tariffed networks.

These tenets will continue to inform the direction of both our proposals to the IETF and of our engineering efforts.

Please try out the prototype, give us feedback and we’ll keep you posted on next steps in the working group. We will also follow up soon with test data resulting from our work on this code.

As we have stated throughout this process, we’re excited for the Web to get faster and more capable. HTTP/2.0 is an important part of that progress and we look forward to improving on the HTTP/2.0 initial draft in collaboration with our fellow working group participants and the Web community at large as we aim for an HTTP/2.0 that meets the needs of the entire Web, including browsers, apps, and mobile devices.

Adalberto Foresti
Principal Program Manager
Microsoft Open Technologies, Inc.
A subsidiary of Microsoft Corporation