> Op 20 feb. 2015, om 09:04 heeft Henning Rogge <hro...@gmail.com> het volgende > geschreven: > > On Fri, Feb 20, 2015 at 8:56 AM, Teco Boot <t...@inf-net.nl> wrote: >> Bad luck, I kindly ask you to pay a little more attention to it. Link >> metrics for wireless links are crucial, but let's not forget wired links. >> >> Some years ago, Thales NLD worked on olsr-lc (link costs, ETT). A plugin >> probed WiFi link speed with large & small packets, filtered out jitter and >> used the outcome as link metric (merged with ETX, I think). For static >> networks and very patient people, it may work. For mobile networks, it is >> far, far to slow. Convergence is tens of minutes. Speed up some timers >> increases load on the wireless links to unacceptable levels. So it died. >> >> But for wired links at homes, this plug&play mechanism could work out well. >> No L2 API needed. > > There is also the "linklayer database" approach I selected for my > olsrd2 implementation. Instead of hardcoding linklayer specific code > into the metric, I split the codebase into "link layer gathering" code > (which is often OS and linklayer specific), generic routing metric > code... and a generic API in between that stores the values. > > This makes it quite easy to adapt the codebase to new linklayer types. >
So you have the placeholder for an automatic ethernet link speed detection. Great! We cannot trust ethernet port L2 feedback. Ports can be connected to switches with multi-rate ports. Could be powerline, wired_over_wireless bridges or other stuff that hides a slow link. In homes, there is no place for protocols that cannot detect and handle such cases. Teco _______________________________________________ homenet mailing list homenet@ietf.org https://www.ietf.org/mailman/listinfo/homenet
