[Cake] New to cake. Some questions

Jonathan Morton chromatix99 at gmail.com
Thu Jun 9 19:27:54 EDT 2016

> why are the vdsl options suffixed with _ptm, but the atm options are not?

Because the “vcmux” and “llc” suffixes are sufficient to imply ATM cell framing.

> is the currently selected set of keywords minimal and complete?

I did some careful research back when I added that feature, including taking some suggestions from you, and according to that: yes, it is correct and complete, and every keyword is related to a real protocol.  Though some are not widely used in practice, they *are* widely supported in ubiquitous consumer-grade equipment.

I haven’t seen any evidence to the contrary; if you have any, please show it, if not, PLEASE SHUT UP about it.

That, by the way, is *me* being blunt to the point of rudeness.

> why name something conservative that will for all peop;e not using an ATM link cost between 9 to 40% of goodput?

The use-case for the “conservative” keyword is essentially: “I know what the raw bitrate of the link is, but I have no sodding clue what overhead it has”.  The goal is to prevent the dumb buffers elsewhere from filling up and undoing our good work.

Yes, it will overcompensate, leading to reduced throughput.  That’s recognised and accepted as far as I’m concerned; the worst corner cases are with very small packets, which frankly matter less.  If you don’t want overcompensation, figure out what the real overhead is and set that.

 - Jonathan Morton

More information about the Cake mailing list