Re: ULE-01 : last byte(s) precision

[Mahesh Sooriyabandara <mahesh@erg.abdn.ac.uk>]

..snip

>
> > (iii) No split Length field if {0,1,2} bytes when PUSI set and {0,1,2,3)
> >
> > bytes when PUSI was not originally set. That would mean skipping if
> > there is <4B remaining!
> No, I think it is one byte less.

Yes, ofcourse it should be one less, my mistake

> I think splitting length and/or end-indicator is a bad idea
> because the receiver must in such case, when there is nor more
> SNDU, the receive a next TS cell to discover that there was nothing
> more !

I also think it may not be worth to add extra complexity to receiver code for

(1 or 2)/184 gain.

But what exactly is the real penalty if we choose to allow splitting of
length
field and/or end indicator?

> the way to work that seems good to me is :
>    PP set, 0,1 bytes left        --> new TS-cell
>    PP set,  >= 2 bytes left      --> pack in this TS-cell
>    PP not set, 0,1,2 bytes left  --> new TS-cell
>    PP not set, >=3 bytes left    --> pack in this TS-cell

Agree

..snip

> Here is a text that I think would remove all ambiguity, and that
> needs not detail the sub-case is PP alreay set or not ...
>
> "If the first two bytes of an SNDU can not be put in in TS-cell,
> then, a new TS cell MUST be started."

This looks good to me. However, may be it is useful to explicitly state the
reason for this two bytes decision (details of the PP set or not set case).

- Mahesh