Re: [Int-area] 答复: 答复: 答复: 答复: Is the UDP destination port number resource running out?// re: I-D Action: draft-ietf-intarea-gue-04.txt

[Tom Herbert <[e-mail]>]

On Thu, May 25, 2017 at 3:14 PM, Joe Touch <[e-mail]> wrote:
>
>
> On 5/25/2017 1:40 PM, Tom Herbert wrote:
>> On Thu, May 25, 2017 at 12:44 PM, Templin, Fred L
>> <[e-mail]> wrote:
>>> If you are talking about the GUE direct encapsulation of IPv4 and IPv6, I
>>> agree
>>>
>>> with the current spec and that direct encapsulation (i.e., with no
>>> additional
>>>
>>> encapsulations between the IP/UDP and inner IP headers) is desirable and
>>>
>>> should remain as part of the spec. I think we may be over-thinking this.
>>>
>> +1. I think a little too much has been inferred beyond the what is
>> actually in draft. Versions are straightforward:
>>
>> - There is a two bit version number field that begins GUE header. The
>> format of the rest of the header depends on the version.
>> - Version 0 defines an encapsulation header that encapsulates by IP
>> protocol number.
>> - Version 1 defined a means for direct encapsulation of select
>> protocols as an optimization. Formats for IPv4 and IPv6 are defined.
>> - Version 2 and 3 are reserved
> I continue to be confused as to why it is more useful to try to make
> decisions based on the first two bits rather than the first four.
> There's near zero benefit, and the harm is that you end up with only two
> reserved versions.
>
If necessary, new version could be defined to be fours bits versions
like version 1 so that gives thirteen possible versions (00 01xx 10xx
11xx) of which three have been defined. v0 is already quite extensible
and generic so I don't see it will be obsoleted any time in the
foreseeable future. Personally, I don't think rearranging the GUE
header is needed at this point.

Tom