The IESG has approved following document: - 'L2TP Active Discovery Relay for PPPoE ' <draft-dasilva-l2tp-relaysvc-08.txt> as an Informational RFC This document is the product of the Layer Two Tunneling Protocol Extensions Working Group. Note: it was originally intended was that this document be on standards track (i.e., it was Last Called as a Proposed Standard). But the document contains a normative reference to RFC 2516, an informational document. Per RFC 2026, Standards Track documents cannot have normative references to informational documents. One consequence of the discussion of the reference issue that occured with this document, is that the document draft-ymbk-downref-00.txt was developed. If and when the downref document (or something like it) becomes a BCP, it is intended that the l2tp document be moved the Standards Track. The IESG contact persons are Thomas Narten and Margaret Wasserman. Technical Summary PPPoE is often deployed in conjunction with L2TP to carry PPP frames over a network beyond the reach of the local Ethernet network to which a PPPoE Host is connected. For example, PPP frames tunneled within PPPoE may be received by an L2TP Access Concentrator (LAC) and then tunneled to any L2TP Network Server (LNS) reachable via an IP network. In addition to tunneling PPP over Ethernet, PPPoE defines a simple method for discovering services offered by PPPoE Access Concentrators (PPPoE AC) reachable via Ethernet from the PPPoE Host. Since the packets used in this exchange are not carried over PPP, they are not tunneled with the PPP packets over L2TP, thus the discovery negotiation cannot extend past the LAC without adding functionality. This document describes a simple method for relaying PPPoE Access Discovery (PAD) messages over L2TP by extracting the PAD messages and sending them over the L2TP control channel. After the completion of setup through the processing of PAD messages, PPP packets arriving via PPPoE are then tunneled over L2TP in the usual manner as defined in L2TP [2]. Thus, there are no data plane changes required at the LAC or LNS to support this feature. Also, by utilizing the L2TP control channel, the PPPoE discovery mechanism is transported to the LNS reliably, before creation of any L2TP sessions, and may take advantage of any special treatment applied to control messages in transit or upon receipt. Working Group Summary There was support for this document in the WG. Protocol Quality This document has been reviewed for the IESG by Thomas Narten.
