Huge thanks to our Platinum Members Endace and LiveAction,
and our Silver Member Veeam, for supporting the Wireshark Foundation and project.

Wireshark-dev: Re: [Wireshark-dev] 12 byte number

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Fri, 22 Aug 2008 10:36:36 -0700

On Aug 22, 2008, at 6:26 AM, Martin Corraine (mcorrain) wrote:

The spec describes the value as a 96-bit identifier that can range from
0 to 2^96 - 1. It serves as an id to track messages. So I think it's
just a very large unsigned number. When you say opaque value, what do
you mean by that?

I mean that it's not interpreted as anything other than a pile of bits - i.e., if it happens to have the value 17, that doesn't mean, for example, that anything referred to by the packet is 17th of a set of things (or 18th of a set of things), or that there are 17 things of some sort, or that something has type 17, or....

It sounds as if that's what the identifier is - just a pile of bits (assuming that message IDs aren't required to be sequential) - so FT_BYTES is the right data type. If it were a value whose numeric value was significant in and of itself (rather than just as a message ID to be matched between, say, requests and replies), that might call for a data type to support larger numeric values.