A note on entropy Re: Are our models correct? Re: Just a very quick remark on system theory Re: Why don't we talk about segments/objects instaead of layers? Re: Lost Layer?
Detlef Bosau <[email protected]> Fri, 21 Feb 2014 22:22:34 +0100
| Newsgroups | gmane.network.end2end |
|---|---|
| Message-ID | <[email protected]> |
Am 21.02.2014 18:10, schrieb Andrew Mcgregor: > You didn't read the paper I was pointing you at then. It models the > window, and all the timers, and includes provision for cwnd clamping and > various other optional features of TCP. > > The limitations you point out are indeed things that happen in naiive > models. Not all models are that naiive. Where I run into trouble with the paper you pointed to is the non decreasing level of entropy in closed systems. I think the model of Hui is a quite straight forward interpretation of VJCC. However, I encountered the most severe problems with wireless networks where you will fail to interpret the propagation of information as a "transport" of energy which is continuously conveyed between buffers / increasing the level of entropy. Perhaps the most important lesson I learned during the past 14 years is that there is no reasonable way to model mobile networks. Meanwhile, I think it is not even necessary to "model" links from a congestion control perspective to model links for a simple reason: Congestion does not occur on a link but on switching nodes. So the idea is to focus on the nodes - and not primarily on the links (which are reasonably dealt with by schedulers.)