Re: [mpls] mail on ISD encodding

[Tony Li <[e-mail]>]

Hi Loa,


>>>> [WG chair hat: off]
>>>> 
>>>> Note that we have a few spare bits in format B.  We COULD in principle,
>>>> change the current proposal to allow format D to follow format B. For
>>>> example, we could change format B to look like:
>>>> 
>>>> 0                   1                   2                   3
>>>> 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>>>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>> |   Opcode    |        Data             |U|IHS|S|  NASL |  NAL  |
>>>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>> 
>>> 
>>> What is U, is it what once was called P?
>> 
>> 
>> Please see the draft.  U is the unknown action handling option.  I have no
>> recollection of what P is or was.
> 
> Plz look at draft-jags-mpls-ps-mna-hdr (you are a co-author) in
> section 4. It allocates the reserved bit in the Format B LSE, as
> a bit indicating post-stack data.


You were expecting us to follow a context switch to an entirely different document?

Yes, I’m proposing moving the U bit to where that draft places the P bit.  If we want to keep the P bit there, then perhaps we shuffle other bits around or remove one bit of data.

T