Wireshark-dev: Re: [Wireshark-dev] NPL to Wireshark compiler/converter
From: Graham Bloice <[email protected]>
Date: Mon, 20 May 2013 21:24:28 +0100

On 20 May 2013 19:15, Guy Harris <[email protected]> wrote:

On Jul 21, 2012, at 11:00 AM, Richard Sharpe <[email protected]> wrote:

> I have started working on an NPL to Wireshark compiler/converter ...

It sounds as if Microsoft's new Message Analyzer tool:


will have its own protocol description language:

        Dave MacDonald 21 Sep 2012 4:09 PM
        I'll answer a couple of questions:

        * Parsers aren't compatible. But, we have a number of ways to bootstrap from various artifacts such as IDL and Microsoft Technical Document sources, and extensible input model. OPN is much more descriptive or higher "fidelity" than NPL. We are looking at a basic NPL bootstrapper but haven't made a determination on the value prop for that.

The language is called Open Protocol Notation:


(and all managed code - "The entire OPN system, including types, actors, endpoints, and flow is implemented in .NET classes.").

Looking at the link it would seem that OPN is a text-based description language that through the magic of the OPN compiler produces a Protocol Object Model (POM) that consists of the .Net classes etc. and is the binary form of the protocol description and the POM is then consumed by the (amongst other things) Message Analyzer run-time component.

So it would seem that others could use OPN, but would have to implement their own compiler\run-time.