3com 3031 Instruccion De Instalación
882
C
HAPTER
63: C
ONFIGURATION
OF
L2TP
sessions. The packets with the same Tunnel ID but different Session ID will be used
in multiplex in a tunnel. Tunnel ID and Session ID in the packet header are assigned
by peer ends.
in multiplex in a tunnel. Tunnel ID and Session ID in the packet header are assigned
by peer ends.
Two typical L2TP tunnel
modes
Tunnel modes of PPP frame between remote system or LAC clients (hosts
performing L2TP protocol) and LNS are displayed as follows:
performing L2TP protocol) and LNS are displayed as follows:
Figure 209 Two typical L2TP tunnel modes
■
Initiated by remote dial-up user. Remote system dials in LAC by PSTN/ISDN. LAC
sends request for tunnel connection to LNS through the Internet. Dial-up users
addresses are assigned by LNS. The authentication and accounting of remote
dial-up users can be accomplished either by LAC side as an agent or by LNS
side directly.
sends request for tunnel connection to LNS through the Internet. Dial-up users
addresses are assigned by LNS. The authentication and accounting of remote
dial-up users can be accomplished either by LAC side as an agent or by LNS
side directly.
■
Initiated directly by LAC users (referring to local users who support L2TP
protocol). In this case, LAC users can send request for tunnel connection
directly to LNS, without an additional LAC device needed. LAC users' addresses
are assigned by LNS.
protocol). In this case, LAC users can send request for tunnel connection
directly to LNS, without an additional LAC device needed. LAC users' addresses
are assigned by LNS.
Call setup flow of L2TP
tunnel
Typical L2TP application network is as follows:
Figure 210 Typical L2TP application network
Call setup flow of L2TP tunnel is shown in Figure 211.
Internet
Remote System
PSTN/ISDN
Internal Server
LAC
LNS
Frame Relay
or ATM
LAC
LNS
LAC client
Internal Server
WAN
PSTN/ISDN
LAC
LNS
PC
PC
PC
Router A
Router B
RADIUS Server
IP network
RADIUS Server
IP network