Re: [LUNI] Ameritech SpeedPath aDSL

From: Martin Maney (maney@pobox.com)
Date: Wed Mar 28 2001 - 14:40:26 CST

  • Next message: Erich Kolb: "[LUNI] Jailing Users"

    On Wed, Mar 28, 2001 at 01:12:24PM -0800, trent wrote:
    > I have absolutley no idea. From what I've read it appears as a
    > connection icon in windows- similar to dial-up networking. By default
    > it disconnects after a certain period of time, and it appears to be a
    > legacy protocol. That's about all I know, until this afternoon, that
    > is. I do have a lot of questions, though. Why authenticate at all?
    > Why not use MAC addy? Why disconnect? Who's on top, SBC or Ameritech?

    One advantage to PPPoE over the very traditional router-based approach that
    Telocity uses (for example) is conservation of IP addresses. The way
    Telocity handles it they use FIVE addresses (1) to provide a single end-user
    machine's connection. With PPP you can cut that down to 2 IP addresses, and
    I'm not certain that the upstream address actually has to be unique - but
    those can come from a non-routable address block if you need to reduce the
    IP address usage.

    The disconnection business is undoubetly viewed as an advantage of using
    PPPoE by Ameritech: they don't WANT customers nailing the line up, if only
    because that makes it practical to run servers, and they don't want
    cusotmers who want to do that. Given PPPoE, requiring authentication is
    probably just simpler, esepcially since that lets them co-opt the existing
    Windows dial-up stuff to manage the connection. And, finally, modeling it
    on dial up probably lets them oversell the IP address space, further
    reducing the number of public IP addresses they need to use per customer.

    Of course there drawbacks to all these things, as there would be to using
    the MAC address for authentication (some cable systems have done that; it
    causes its own annoyances).

    (1) 4 in the subnet (2 usuable, 1 of those is the "modem's" NIC) plus the Ip
    address the upstream side of the "modem" uses. I suppose you could count a
    fractional address for the per-user share of the level up, but that's
    probably not very different than what everyone else does. I guess.

    -=-
    Linux Users Of Northern Illinois: General Discussion Mailing list.
    For unsubscription, archives, and announcements only see http://luni.org



    This archive was generated by hypermail 2b29 : Wed Mar 28 2001 - 14:43:25 CST

  •