RFC 3931:Layer Two Tunneling Protocol - Version 3 ...
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... nodes across an IP network. Additional documents are expected to be published for each L2 data link emulation type (a.k.a. pseudowire-type) supported by L2TP ...
... cross-connect an L2TP session directly to a data link, we refer to it as an L2TP Access Concentrator (LAC ...
... LAC or LNS, depending on whether tunneled frames are processed at the data link (LAC) or network ...


... link layer being tunneled and the network data traversing the data link, this is sufficient in many cases to enforce packet order on frames that require it (such as end-to-end ...
... sufficient in many cases to enforce packet order on frames that require it (such as end-to-end data link control messages), while not on IP packets that are known to be resilient to packet reordering ...



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