QTECH SmartEdge 600 Configuration - Manual (Page 8)

Configuring Authentication, Authorization, and Accounting
accounting message or tears down the subscriber session, depending on the
configured action to perform.
If the RADIUS attribute does not include the direction to which the limit is
applied, the downstream direction is assumed. If no limit is included, the traffic
volume is unlimited in both the directions and is not monitored. If a limit of 0
is configured for a direction, traffic is treated as unlimited in that direction and
is not monitored.
VSA 113 is also supported in a subscriber reauthorize Access-Accept message.
1.1.2.4 Binding Order
If a subscriber circuit has been configured with a dynamic binding, using the
bind authentication
command (in the circuit’s configuration mode),
AAA uses subscriber attributes in messages received during subscriber
authentication to determine which IPv4 address (and the associated interface)
to use when binding the subscriber circuit.
By default, the router considers L2TP attributes before considering RADIUS
attributes. You can reverse this order so that the IPv4 address provided in the
RADIUS record is used before one provided by L2TP.
1.1.2.5 IP Address Assignment
By default, the router uses a round-robin algorithm to allocate subscriber
IPv4 addresses from the IP pool. You can also configure the router to use a
first-available algorithm.
AAA typically assigns an IPv4 address to a PPP subscriber from an IP pool
after receiving an Access-Accept packet from a RADIUS server. However,
you can configure AAA to provide an IPv4 address from an IP pool in the
Framed-IP-Address attribute in the RADIUS Access-Request packet. This IPV4
IP address is provided to the RADIUS server as a preferred address. If there
are no unassigned IPv4 addresses in the pool, the authentication request is
sent without an IPv4 address.
The RADIUS server may or may not accept the address ; Table 1 lists the
RADIUS server responses and the corresponding router actions.
Table 1 RADIUS Server Response and Router Actions
RADIUS Server Response Corresponding Router Action
Framed-IP-Address attribute
contains 255.255.255.254,
0.0.0.0, or is missing. The router assigns preferred IPv4 address.
Framed-IP-Address attribute
contains a different IPv4
address. The router assigns the IPv4 address in the
Framed-IP-Address attribute and returns the
preferred IPv4 address to its pool.
4 61/1543-CRA 119 1170/1 Uen L | 2012-12-04