Toerless Eckert <[email protected]> wrote:
    > Why is the document not using a formal language to define the
    > syntax/semantic of its formatting ? Would CBOR/CDDL not be a
    > good candidate ?  Any other ?

Because pcapng is at least 10 years old, and pcap is around ~33 years old.
If we designed it today, it would definitely be CDDL/CBOR.
We probably want to design new extensions that way too.

It's all 32-bit type followed by 32-bit length TLV.
This mechanism occurs repeatedly everywhere, I wish the IETF had a name for it.

    > B) Just quickly browsing through the document: One of the core
    > aspects unresolved seems to be the rich filter language. It might
    > be helpfull to separate this out into a separate document even if
    > just so as to be able to finish this document faster. Especially
    > when using a formal language, it might also be easier to also
    > document the filter sematic used by being able to point to the
    > template.

Scratching my head.
pcapng does not define any filter language.
Nor does pcap.

pcapng does allow the filter string (in whatever language), to be included as a 
comment.
At no point do these documents attempt to standardize the pcap filter
language, nor the BPF codes.

    > C) Even more quickly looking at the TOC, i couldn't find anything that
    > would report the identity of the reporting entity and characterization
    > of it. e.g.: which cpu-core, linecard, version of the reporting
    > software, self-claimed accuracy, possible limitations (likelyhood
    > of packet drops etc. pp).

In pcapng, section 4.2, the Interface Description Block.
    | if_name        | 2    | variable            | no                |
    | if_description | 3    | variable            | no                |
    | if_IPv4addr    | 4    | 8                   | yes               |
    | if_IPv6addr    | 5    | 17                  | yes               |
    | if_MACaddr     | 6    | 6                   | no                |
    | if_EUIaddr     | 7    | 8                   | no                |
    | if_speed       | 8    | 8                   | no                |
    | if_tsresol     | 9    | 1                   | no                |
    | if_tzone       | 10   | 4                   | no                |
    | if_filter      | 11   | variable, minimum 1 | no                |
    | if_os          | 12   | variable            | no                |
    | if_fcslen      | 13   | 1                   | no                |
    | if_tsoffset    | 14   | 8                   | no                |
    | if_hardware    | 15   | variable            | no                |
    | if_txspeed     | 16   | 8                   | no                |
    | if_rxspeed     | 17   | 8                   | no                |

(Yes, it needs IANA considerations.  Probably some integration with more
current YANG values in a new block type would also make sense)

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        |    IoT architect   [
]     [email protected]  http://www.sandelman.ca/        |   ruby on rails    [




--
Michael Richardson <[email protected]>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide




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