Does PPPoE support data compression?

Does PPPoE support data compression?

Post by lash » Sun, 06 Jul 2003 05:56:04



Since PPPoE is based on the PPP protocol (which
supports data compression, from what I understand),
does PPPoE support data-compression?

If so, is that a feature most ISPs and home
routers (Linksys, Netgear, D-Link, etc.) implement?

 
 
 

Does PPPoE support data compression?

Post by David H. Lipma » Mon, 07 Jul 2003 21:54:25


Yes...

and

Yes.

Dave

 
 
 

Does PPPoE support data compression?

Post by John D Loo » Mon, 07 Jul 2003 23:15:18


The ppp runs end to end from your PC/router to the ISP, and there is
certainly much of the ppp options in there.
I don't really think many providers use much compression on the data like
analog modems can perform, just shortening of the header fields.
The pppoe only runs between your PC/router and the (typically) Telco
termination at the "Access Concentrator."  IIRC there is some header
shortening that can occur, but no data compression.  Here is a short
description of the pppoE transaction:
http://bellsouthpwp.net/j/d/jdloop/adsl/ShastaBBG/
RFC 2516 is very short, and almost understandable:
http://www.faqs.org/rfcs/rfc2516.html
J
--
Check my web site for tips on homenetworking and safe computing
www.pccitizen.com


Quote:> Since PPPoE is based on the PPP protocol (which
> supports data compression, from what I understand),
> does PPPoE support data-compression?

> If so, is that a feature most ISPs and home
> routers (Linksys, Netgear, D-Link, etc.) implement?

 
 
 

Does PPPoE support data compression?

Post by Tim Keatin » Tue, 08 Jul 2003 21:30:20


On Sun, 6 Jul 2003 10:15:18 -0400, "John D Loop"


>The ppp runs end to end from your PC/router to the ISP, and there is
>certainly much of the ppp options in there.
>I don't really think many providers use much compression on the data like
>analog modems can perform, just shortening of the header fields.
>The pppoe only runs between your PC/router and the (typically) Telco
>termination at the "Access Concentrator."  IIRC there is some header
>shortening that can occur, but no data compression.  Here is a short
>description of the pppoE transaction:

If they did compression.. It would blow goats even more..
  Ever notice the extra time latency?  Especially during  peak times?

  That's the poor little concentrator router cpu(s) trying to keep up
with de/encapsulating PPPoE traffic for 1000's of active IP's.

  Adding compression would add to their work load at least 100x..
(I.E 8000 customer CPU's de/compressing verses 1 to 8 relativity slow
cpus in PPPoE concentrator router)..  choke.. choke.. choke..

-----

It been a while since I measured the effect of PPP compression for
DIAL-UP modem pools. During peak ISP usage times it could add several
hundred ms of extra delay to a packet.   (Ping to local ISP
system/router, at most 1 or 2 hops from the concentrator).

 
 
 

Does PPPoE support data compression?

Post by ab.. » Tue, 08 Jul 2003 21:44:46



> If they did compression.. It would blow goats even more..
>   Ever notice the extra time latency?  Especially during  peak times?
>   That's the poor little concentrator router cpu(s) trying to keep up
> with de/encapsulating PPPoE traffic for 1000's of active IP's.

Only when you buy service from chicken shit vendors who overload
their facilities - Stac compression works extremely well on ISDN
for example.

Billy Y..

 
 
 

Does PPPoE support data compression?

Post by John D Loo » Wed, 09 Jul 2003 08:45:15




> > If they did compression.. It would blow goats even more..
> >   Ever notice the extra time latency?  Especially during  peak times?

> >   That's the poor little concentrator router cpu(s) trying to keep up
> > with de/encapsulating PPPoE traffic for 1000's of active IP's.

> Only when you buy service from chicken shit vendors who overload
> their facilities - Stac compression works extremely well on ISDN
> for example.

> Billy Y..

And remind me how much faster ADSL is than ISDN.......... About 10 times
maybe?
J
--
Check my web site for tips on homenetworking and safe computing
www.pccitizen.com
 
 
 

Does PPPoE support data compression?

Post by David H. Lipma » Wed, 09 Jul 2003 10:28:58


Aren't you comparing apples to oranges ?

Which ADSL are you referring to ?  ISDN is fixed, ADSL varies.

Dave

 
 
 

Does PPPoE support data compression?

Post by John Loo » Wed, 09 Jul 2003 21:14:30


In our experience maybe 90% of the customers are running 1 Mbs+
Maybe it is because of all the RTs BS has.
John

--
www.pccitizen.com Tips on home networking and safe computing


Quote:> Aren't you comparing apples to oranges ?

> Which ADSL are you referring to ?  ISDN is fixed, ADSL varies.

> Dave

 
 
 

Does PPPoE support data compression?

Post by ab.. » Thu, 10 Jul 2003 02:03:34



Quote:> Aren't you comparing apples to oranges ?

No, compression is compression, period.  You either have hardware
that can cut it, or not.  But if you do there is something to be
gained for some types of data - excluding the obvious zipped files,
jpegs and all the other already compressed stuff.

Massive amounts of cpu power are pretty cheap these days, there's
no reason why it can not be a cost effective thing - unless you're
dealing with greedy net vendors and phone companies.

Billy Y..

 
 
 

Does PPPoE support data compression?

Post by John Nava » Thu, 10 Jul 2003 02:27:45


[POSTED TO comp.dcom.modems.cable - REPLY ON USENET PLEASE]




>> Aren't you comparing apples to oranges ?

>No, compression is compression, period.  You either have hardware
>that can cut it, or not.  But if you do there is something to be
>gained for some types of data - excluding the obvious zipped files,
>jpegs and all the other already compressed stuff.

When you look at typical Internet data, the gain is relatively small.

Quote:>Massive amounts of cpu power are pretty cheap these days, there's
>no reason why it can not be a cost effective thing - unless you're
>dealing with greedy net vendors and phone companies.

The amount of horsepower to do real-time compression at broadband speeds is
still expensive, and not justified from a cost standpoint, in part because
consumer broadband typically exceeds the speed at which data is being
transmitted.

p.s.  Broadband providers are hardly greedy -- consumer broadband is a
bargain, and not a lucrative business.

--
Best regards,
John Navas     <http://navasgrp.home.att.net/>
     CABLE MODEM/DSL GUIDE:  <http://Cable-DSL.home.att.net/>