Implementing L2Tp; Sequence Of Events On The Lac - Juniper JUNOSE SOFTWARE 11.2.X - BROADBAND ACCESS CONFIGURATION GUIDE 7-20-2010 Configuration Manual

Implementing L2TP

Sequence of Events on the LAC

Copyright © 2010, Juniper Networks, Inc.
Table 68: L2TP Terms (continued)
Term Description
Peer In the L2TP context, refers to either the LAC or LNS. An LAC's peer is an LNS,
and vice versa.
Proxy Authentication data from the PPP client that is sent from the LNS as part of
authentication a proxy LCP. Data might include attributes such as authentication type,
authentication name, and authentication challenge.
Proxy LCP LCP (Link Control Protocol) negotiation that is performed by the LAC on behalf
of the LNS. Proxy sent by the LAC to the LNS containing attributes such as the
last configuration attributes sent and received from the client.
Remote system An end-system or router attached to a remote access network, which is either
the initiator or recipient of a call.
Session A logical connection created between the LAC and the LNS when an end-to-end
PPP connection is established between a remote system and the LNS.
NOTE: There is a one-to-one relationship between established L2TP sessions
and their associated PPP connections.
Tunnel A connection between an LAC-LNS pair consisting of a control connection and
0 or more L2TP sessions.
The implementation of L2TP for the E Series router uses four levels:
System—The router
Destination—The remote L2TP system
Tunnel—A direct path between the LAC and the LNS
Session—A PPP connection in a tunnel
When the router has established destinations, tunnels, and sessions, you can control the
L2TP traffic. Making a change to a destination affects all tunnels and sessions to that
destination; making a change to a tunnel affects all sessions in that tunnel. For example,
closing a destination closes all tunnels and sessions to that destination.
The E Series router creates destinations, tunnels, and sessions dynamically, as follows:
The client initiates a PPP connection with the router.
1.
The router and the client exchange Link Control Protocol (LCP) packets. For details
2.
about negotiating PPP connections, see the Configuring Point-to-Point Protocol
chapter in JunosE Link Layer Configuration Guide.
Chapter 11: L2TP Overview
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