Re: [babel] info-model: message log

[Juliusz Chroboczek <[e-mail]>]

>> (Note that picking a dump format doesn't mean we can parse it -- there's the
>> small matter of the encapsulation used, which could be 802.2, radiotap, raw
>> IPv6, or something else.  Do we need to specify that?)

> Encapsulation is the job of the management protocol. The info model will
> allow the file to be exposed...

That's not what I meant.  Pcap and pcapng contain a sequence of frames --
these frames can be using a number of different encapsulations.

Here are the cases I'm familiar with:

  - pcap can contain a sequence of Ethernet frames;
  - pcap can contain a sequence of 802.2 SNAP frames;
  - pcap can contain a sequence of radiotap frames which themselves
    contain whatever is carried by the 802.11 link (typically 802.2 SNAP).

Is it legal for an implementation to expose, say, PPP frames in the pcap
file?  Do we need to formalise the allowed encapsulations contained within
the pcap file, or are we going to assume implementers do something
reasonable?

(I'd argue in favour of being liberal here -- being restrictive might
cause issues if at some point Babel is carried over exotic link layers,
and after all one of Babe's strenghts is that it's link-layer-agnostic.
But I think it deserves discussion.)

-- Juliusz