On 11/15/14, 7:57 AM, "Margaret Wasserman" <[email protected]> wrote:
> >On Nov 15, 2014, at 7:40 AM, Juliusz Chroboczek ><[email protected]> wrote: >> Mark, please scratch my previous offer to implement a stub-only variant >>of >> Babel. Please let me know how much flash and RAM you give me, and I'll >> do my best to fit Babel into that amount. > >In the impromptu meeting on Thursday, I believe that James Woodyatt said >that his nodes have 64K of ram and that code executes-in-place out of >ROM. He didn't say how much of that 64K is currently used for data for >other parts of the system. > >You have said that the Babel implementations have a sole requirement for >libc, but I don't know if they also require Linux? > >My understanding is that the Nest boxes have their own mechanisms for >routing between themselves, and that Nest does not plan to change that >protocol for home deployments. They are hoping that one or more of their >units within a home deployment will be able to connect to a homenet >network, providing access to the homenet without running a homenet >routing protocol on all of their nodes or serving as a transit network >for other traffic within the home. > >I think you may see a similar requirement for SEP (Smart Energy Profile) >nodes that run RPL for routing within a IEEE 802.15.4 low-power wireless >network. They will continue to route among themselves, but may want a >way to attach their stub network to a homenet network. Some of these >nodes have similar capabilities to the Nest nodes that James has >described. Since the assumption is that the device runs HNCP anyway, the intent is to use that for the stub-only routing. Thanks, Acee > >>> I mean, babel, for example, is like, 61k, on mips with the sole >>> dependency on libc. >> >> I'm seeing 90kB on AMD64. That includes three extensions to the core >> protocol (source-specific routing, diversity routing, support for >>overlay >> networks), but not the cryptographic MAC extension. > >Are the current Babel implementations designed to execute-in-place out of >ROM? >> >> Memory usage is less than 100kB in typical deployments. A (pessimistic) >> upper bound on memory usage (not counting malloc overhead) in is given >>by >> >> (88 * neighbours + 48 * total_routers) * redistributed_prefixes >> >> where a redistributed prefix is counted once per redistributing router >> (e.g. two distinct edge routers redistributing the default route counts >>as >> two). This means that if you have a network with 100 routers >>advertising >> 400 prefixes, a router with 5 neighbours needs at most 200 kB of RAM. > >I don't know what numbers we are using to consider scaling for homenet >networks. Mark, are there back-of-the-envelope numbers for what we >consider "a typical homenet" and a "largest possible homenet" that we >could use to determine how much RAM Babel would be likely to use in those >cases? > >Margaret > >_______________________________________________ >homenet mailing list >[email protected] >https://www.ietf.org/mailman/listinfo/homenet _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
