Re: [mpls] mail on ISD encodding

[[e-mail]]

Tony,


Inline plz.

>
> Hi Jie,
>
>> On Mar 11, 2024, at 2:18 AM, Dongjie (Jimmy) <[e-mail]>
>> wrote:
>>
>> Then your proposal of occupying all the reserved bits in format B for
>> NAL would prohibit the introduction of PSD or other possible extensions
>> in future.
>>
>> IMO some reserved bits need to be kept in the NAS encoding.
>
>
> That’s fine.  As I suggested, we can steal another data bit for a
> reserved bit.
>
So you mean we should first break what is not broken, then "steal a bit"
for the U-bit, that was there from the start? Or did you mean steal for
the p-bit which also seems unnecessary, since the R-bit sits there in
draft-ietf-mpls-mna-hdr, and draft-jags-mpls-ps-mna-hdr nicely allocates
it as a p-bit? How about just leaving the bit allocation as is?

However, there is one thing about where the allocations are done.

The p-bit is one of the ISD-flags, it points at OSD, but it is really a
piece of the ISD. Should be allocated in the draft-ietf-mpls-mna-hdr.

Also the instruction (for R-bit), "set to zero when sending and ignore
when received" is problematic. Let us forget about the R-bit and put the
p-bit where it belongs. There should be a description of how
a non-PSD capable node treats a packet with the p-bit set.

/Loa

> T
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