On Fri, 4 Feb 2000, Michal Ostrowski wrote:
> jamal writes:
> >
> > So lets try to identify what the other concerns are.
> > Michal, i think this is a very good compromise if you can pull it.
> > Maybe it will start with just PPPOE; and i suspect L2TP to follow
> > it needs something similar.
>
> I think we'd need to examine L2TP and see just how well it can
> co-exist with PPPoE/PPPoATM. Doing PPPoE is easy... figuring out how
> to do it in a manner which can co-exist with PPPoX is hard.
>
Not really.
I'll take a look at L2TP and (i hate promising this because i am
overloaded) do a port of Mark Spencers user space l2tp
> > I think the socket solution is acceptable if you can make it to be
> > for more than just pppoe. This is my opinion however.
> > I am afraid some of the people that i know to be concerned of this whole
> > socket idea havent spoken yet ;-> The words "maintainance nightmare" were
> > not really mine.
>
> Yes... I'm really looking forward to hearing Andi's, Paul's and Dave's
> comments (if they ever manage to read through all of the stuff we sent
> around yesterday).
>
I am afraid these are some of the people who were staing that. They
probably want to see if we reach an agreement or not ;-> I am also
scared that someone is gonna shout "SOCK_PACKET extensions" (as did the
last poster -- thats why i didnt respond).
> >
> > sid should be enough for pppoe, no?
>
> 99.99999% of the time sid alone suffices. However, you have a problem
> if you have multiple connections --- because the remote access
> concentrator's may all assign you the same sid, in which case you must
> identify them by MAC address as well. My view is that you can think
> of sid's as analogous to TCP/UDP ports --- they're useless without an
> IP address.
>
true.
> Let's not be quick to jump to conclusions as to how PPPoE will be
> used. I've heard a rumour that PPPoE is being considered for use here
> at the University of Waterloo to provided authenticated ethernet
> access at public ethernet access points. Such a solution makes some
> sense since one could leverage the existing RADIUS/PPP infrastructure
> used to provide dial-up access. The point here is is that we may see
> PPPoE being used beyond the traditional ADSL context (funny how ADSL
> is already "traditional").
>
I think i have a very good feel to where PPPOE is going.
It is about services -- currently the only service is really access; and i
think that you might end up seeing the discovery part being extended for
some things. I would like to extend it myself and i dont think the
"proprietary tag" they have there already is good enough.
> >
> > There is always a unique way to identify a flow regardless of the
> > protocol. Look at the way UDP does it (because it is simple).
> >
>
> I don't understand what you mean by this, please elaborate (or refer
> to a specific code fragment).
>
I was refering to the hashing used. Sorry dont have access to code right
now;
A TCPI/IP flow could be uniquely hashed by the five tuples: src/dst port,
src/dst IP and protocol.
> My concern is that you need to know something about the protocol to be
> able to identify the flow, since you need to be able to parse the
> packet header and extract those bits that identify the stream.
And i think every of the PPPOXs will have something unique; so the hashing
is not shareable.
> Is it possible to find some sort of abstract addressing scheme which
> can be used by PPPoE, PPPoATM, L2TP, etc...? (Essentially is it
> possible to come up with a sockaddr_pppox which is appropriate for all
> of them?) The answer to that IMO will determine whether or not you
> can make AF_PPPOX work. I don't know the answer to that.
I'll take a look at L2TP sometime this evening or sometime tommorow.
You can easily figure the ATM one (or i could look at that too).
>
> As a side note... I've been informed that our favorite PPPoE-using
> ADSL provider's network architecture (Bell Nexxia) includes PPPoE,
> L2TP, and PPPoUDP. By that I mean that it is actually possible for
> you to send a packet which is carried by all of these protocols before
> it reaches your ISP's IP network (in the case that your ISP is not
> Sympatico). If your ISP is Sympatico, then you get to skip the
> PPPoUDP step.
>
Hmm... I know someone who is doing PPPTP over PPPOE ;->
I do tunnel over IPSEC to work via PPPOE myself;->
I think you'll see a lot of these VPNish types offered as services;
You discover them, you select based on pricing, QoS paramaters etc; doesnt
matter what the "ISP today" is. I split my user space code into some sort
of libraries -- still in very primitive stages so that i can easily stash
GUIs etc in anticipation of this. So in the very near future this will
start happening, if the CRTC gets its rulings imposed. You ask for access
service, 10 ISPs respond with their AC names and a few other parameters.
You select one. Dont ask me about the billing ;-> In the future ADSL will
part of your phone bill and the people resonding to you will not be
offering you access but rather some other value add service. You will get
a feel that Access is free since it is bundled in your phone bill ;->
I hear cable modem is moving to this path as well ;->
It makes a lot of sense if you think about the future.
cheers
jamal
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