L2TP Access Concentrator
Supported LAC Service Configurations for PDSN Simple IP ▀
Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
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Supported LAC Service Configurations for PDSN Simple IP
LAC services can be applied to incoming PPP sessions using one of the following methods:
Attribute-based tunneling:
This method is used to encapsulate PPP packets for only specific users, identified
during authentication. In this method, the LAC service parameters and allowed LNS nodes that may be
communicated with are controlled by the user profile for the particular subscriber. The user profile can be
configured locally on the system or remotely on a RADIUS server.
PDSN Service-based compulsory tunneling:
This method of tunneling is used to encapsulate all incoming PPP
traffic from the R-P interface coming into a PDSN service, and tunnel it to an LNS peer for authentication. It
should be noted that this method does not consider subscriber configurations, since all authentication is
performed by the peer LNS.
Each LAC service is bound to a single system interface configured within the same system context. It is recommended
that this context be a destination context as displayed in the following figure.
Figure 37.
LAC Service Configuration for SIP
Attribute-based Tunneling
This section describes the working of attribute-based tunneling and its configuration.