Talk:Point-to-Point Protocol over Ethernet

I have added Content from the German article to add to this one. The following points need clearing up:

• The first paragraphs of both articles are very different, and so I have left it alone - but that does not mean it could modified....

• There are no references, although I suppose the RFCs define it ( ? ) .

• The usual caps / technical terms issue.

Regards

ACH 17:00, 17 December 2005 (UTC)

"Reasons"

The article states that the reasons for using PPPoE is that Ethernet is connection-less and has no support for user authentication. However, it fails to explain why the network access server can't just use PHY information (like what actual telephone line the data is coming via) instead of adding an extra protocol layer. I haven't actually worked with a DSLAM, so I'm afraid I can't contribute this information myself. Dolda2000 18:19, 30 May 2007 (UTC)

Your question is probably more relevant at the PPP discussion page. I am assuming that you are asking why we need PPP at all when we can identify the individual links at the server. The basic reason is to hide the differences between the different kinds of physical links (async, serial, frame-relay, ISDN etc..) and their unreliability and provide a standard interface to IP. In fact one of the goals of IP itself was to hide the hardware differences and provide a single interface to any network application (like http). They just do this thing at every layer. For more details refer the PPP page. This article just specifies why it became necessary to run PPP over ethernet and why PPP originally did not run over it. Mukesh.mv 08:59, 4 July 2007 (UTC)

Actually, that isn't quite what I'm asking, because PPP has an obvious need over e.g. serial links, where there is no natural datagram boundary or standardized semantics for how to handle broadcast requests and such things. Ethernet, on the other hand, already has all those things that PPP is supposed to provide to links that don't have them. That's why I don't understand why anyone would want to use PPP over Ethernet. Dolda2000 18:34, 18 July 2007 (UTC)

Some answers -

* The DSLAM actually aggregates traffic from individual phone lines into one or two high performance links. Hence we cannot manitain user information that way.

* Ethernet does not have all the things that PPP provides. Ethernet is designed for broadcast mediums and is not a point-to-point protocol. Though it has a datagram boundary/multi protocol encapsulation etc., it lacks connection establishment, user authentication mechanisms. One way would have been to build this over ethernet itself. But since PPP already existed they just ran it over ethernet to solve the problem instead of inventing a new mechanism.

* Existing software at the server end would have to be changed if PPP was not used.

Hope this helps. Mukesh.mv 14:49, 5 August 2007 (UTC)

IP over ethernet is terriblly insecure! Anyone can send fake arp broadcasts or mac floods to spy on traffic! Anyone can take any IP address they like! There is no way to authenticate users. This is tolerable (though far from ideal) for an internal network in a company but totally unsuitable for a system where anyone can pay a small monthly fee and connect any equipment they like. PPP on the other hand establishes a well authenticated point to point link with strong authentication and if required encryption. Plugwash 00:03, 6 August 2007 (UTC)

Article title

Why is this article titled PPPoE, when every other protocol in the Internet protocol suite has its name spelled out? I propose that we move the page to Point-to-Point Protocol over Ethernet, to match the article for PPP. — EagleOne\^Talk 20:55, 18 December 2005 (UTC)

I agree - in the interest of consistency. One could just put a redirect at PPPoE. ACH 10:21, 19 December 2005 (UTC)

I posted a similar request on Talk:PPPoA today. If no one objects in a coulpe of days, I'll move the pages and fix the redirects. — EagleOne\^Talk 17:58, 20 December 2005 (UTC)

PPPoE and atm

ADSL is afaict atm based yet some providers use PPPoE rather than PPPoA or even allow both. How exactly does this fit in? Plugwash 01:45, 2 January 2006 (UTC)

"Fit in" in what sense? Yes, ADSL is ATM-based. Some providers run bridged Ethernet over ATM, and then run PPPoE over that. Some providers run PPPoA, and avoid using Ethernet at all. Some providers run bridged Ethernet over ATM and don't bother running PPPoE over that. Guy Harris 00:42, 28 October 2006 (UTC)

Password

How does the use of passwords in PPPoE links differ from the alternatives? Just what alternatives are used on DSLs where PPPoe is not? Jim.henderson 15:03, 25 October 2006 (UTC)

Some ADSL connections use bridged Ethernet over ATM without running PPPoE, and don't use passwords at all. Guy Harris 16:32, 25 October 2006 (UTC)

Correct...the article states Verizon FIOS connections are not using PPPoE. The article itself should also be edited to state that both Verizon FIOS and Verizon DSL services do NOT use PPPoE. I know this because I use regular Verizon DSL in both Florida and New Hampshire, and neither service uses PPPoE. SarasotaSlim (talk) 13:05, 6 June 2010 (UTC)

Ethernet is atm based and can use a variety of schemes for transmitting IP over that, including PPPoE (i don't entirely understand how this works, i guess it uses atms ethernet like emulation layer or something) PPPoA and a variety of older protocols. Both PPP variants handle passwords in the same way as any other PPP variant (e.g. pap or chap), most of the other schemes afaict don't do passwords at all.

Ethernet is not ATM-based. See the Ethernet article to see how Ethernet works.

To understand how PPPoE works, see the PPPoE article and the RFC for PPPoE. It doesn't use anything about ATM. (ATM's "Ethernet-like emulation layer" is "LAN Emulation" or "LANE". It emulates an Ethernet or Token Ring LAN over ATM.)

PPPoA doesn't involve Ethernet at all. That's what the "oA" prt of "PPPoA" indicates - it runs PPP directly over ATM without Ethernet being involved.

The standard scheme for transmitting IPv4 over Ethernet doesn't involve any protocols other than Ethernet, ARP, and IPv4 itself; see RFC 894. The standard scheme for transmitting IPv6 over Ethernet involves Ethernet, IPv6 itself, and assorted other protocols.

Bridged Ethernet over ATM doesn't involve PPP at all, and doesn't use passwords. See RFC 2684.

Well, thanks, everybody, especially the ones who remembered to sign their names. My problem with a relative's two years old Verizon DSL connection was fixed by calling the toll free help number and the guy in India talked me through putting the password in correct places, namely both the Actiontec router and a place in XP Networking. In my own Verizon DSL installed this summer (one computer under WinMe and one 98SE) there is no password. No security measures in the link, router, or computers that I can see. Whether either of these ADSLs have ATM or bridged Ethernet or both or neither, I have no idea.

Why someone at Verizon two years ago thought consumer DSL needed the security, verification, compression etc features of PPPoE, I may never know, but fortunately they changed their mind and no new users are afflicted with security that makes insecurity. Ought the article say whether PPPoE is rare or common, new or obsolete, in consumer DSL and CATV Internet? Jim.henderson 05:24, 28 October 2006 (UTC)

ADSL always has ATM. Whether it has bridged Ethernet over ATM without PPPoE, bridged Ethernet over ATM with PPPoE, PPPoA without any Ethernet, or whatever, is up to the provider. I've no idea what Verizon have done over time; the page at [1] suggests that "ADSL Data Network Release 1" might have used either bridged Ethernet over ATM without PPPoE ("IP over Ethernet over ATM") or bridged Ethernet over ATM with PPPoE ("PPPoE over ATM"), and that "ADSL Data Network Release 2" might have used either bridged Ethernet over ATM with PPPoE or PPPoA ("PPP over AAL5"). Perhaps there's a "Release 3" that went back to bridged Ethernet over ATM without PPPoE. (That document says "Bell Atlantic", which indicates how old it is. :-)) Guy Harris 07:01, 28 October 2006 (UTC)

Section for average user

Could a short section be added that gives the average user a simpler description? For example...

• Where does the average user set PPPoE? Must it be set on each computer in the local network?
• Why would PPPoE be necessary for DSL but (apparently) not for cable modems? Doesn't the Ethernet network itself (including router etc.) look the same in both cases? So why would the type of modem (DSL versus cable) make a difference?
• Regarding the statement "By using PPPoE, users can virtually "dial" from one machine to another over an Ethernet network", what does this typically look like to the user? Don't most modern operating systems already provide this?

This would help average readers better understand what PPPoE is actually used for.

3dimen (talk) 23:27, 20 June 2008 (UTC)

PPPoEoE vs PPPoEoA

I'm struggling to understand the difference here - the section 'How PPPoE fits in' seems to imply that they both run over ATM and both involve RFC2684 bridging. Can someone make this a bit clearer? Kisch (talk) 12:48, 4 August 2008 (UTC)

Basically, PPPoEoE takes the whole ethernet frame with its embedded PPPoE packet and encapsulates it into ATM frames on the other side, effectively bridging the ethernet network (i.e. making it appear that there's a virtual ethernet network extending from the client's site to the ISP's.) PPPoEoA, on the other hand, takes the embedded PPPoE packets out of the ethernet frames and encapsulates them in ATM, more of a relaying or forwarding process. -- Steved424 (talk) 09:23, 1 June 2009 (UTC)

Changed to PPPoE connection

My service provider had an outage of late. eventually after phoning a couple of times resetting my router to default etc. they told me to set up a PPPoE connection, now it works. On my mega105wr router my internet led does not come on, only the dsl led is on. My router in the web based management does not show it has a ip address or default gateway. Why is this. —Preceding unsigned comment added by Steggos (talk • contribs) 07:51, 8 October 2008 (UTC)

With PPPoE, your "router" is actually operating below the IP layer, merely forwarding PPPoE packets from the ISP to your PC. In this setup, it's your PC which runs PPP, and so gets an IP address assigned and needs a default route. Because of this, you should make sure you have a firewall running on your PC - such as the one that comes with (I think) XP SP2 and later. -- Steved424 (talk) 09:28, 1 June 2009 (UTC)

broadband connection

most users are basically intrested in the way computers are connected to intrenet. so i'va added a introduction with the help of a block diagram to create the intrest of newbie about the layers of protocol and devices involved in the connection to internet and thier importane.

regards --gursimar singh mohar 15:01, 26 December 2009 (UTC) —Preceding unsigned comment added by Simar mohar (talk • contribs)

Overhead

When the overhead for a 1492 byte payload is calculated as ${\frac {1500-1492}{1492}}={\frac {8}{1492}}$, I would expect to calculate the overload for a 60 byte payload as ${\frac {8}{60}}$ which results in 13.33 %. Therefore I doubt the mentioned 15.3 %. -- Simon04 (talk) 15:31, 27 February 2011 (UTC)