Jonathan Morton <chromati...@gmail.com> wrote: >> Jonathan Morton <chromati...@gmail.com> wrote: >>> I haven’t yet found a robust way to automatically sense link capacity from >>> the upstream side. You’ll therefore need to set a conservative static >>> value for the uplink capacity. >> >> As the maintainer of a PPPoE concentrator, and operator of some networks, >> I've been considering whether one can estimate the bandwidth using round >> trip PPP IPCP keep alives. Clearly, if both ends participate in time >> stamping then it is much better, but I've been wondering if we can do some >> incremental deployment on one side or the other. >> >> Sadly, I mostly just think about this while cycling; I haven't written any >> code yet.
> In most PPPoE deployments I know about, there is also a modem from > which the actual, precise link rates can usually be queried. Where > that’s not the case, IPCP (or is it LPCP?) probes would be a reasonable > workaround, but it must still be understood that the signal it provides > is only valid under saturating traffic, which complicates > implementation. Yes, you are rtight, I want to do LPCP echo requests. The modem might know what speed it has with the tower/DSLAM, but won't know how congested the backhaul link is. There are some third party/white label 3G arrangements in Canada that use PPP/L2TP back to the third-party provider, but most route the IPv4 (only) packets via IPsec or MPLS. -- ] Never tell me the odds! | ipv6 mesh networks [ ] Michael Richardson, Sandelman Software Works | network architect [ ] m...@sandelman.ca http://www.sandelman.ca/ | ruby on rails [ _______________________________________________ Cerowrt-devel mailing list Cerowrt-devel@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cerowrt-devel