QTECH SmartEdge 100 PPP and PPPoE - Manual (Page 7)

Overview
If the remote PPP device is a router (or the remote segment of any other
encapsulation type contains a router), it might be necessary to configure one or
more static routes whenever the link is brought up. This is accomplished by
one or more Routing Information Protocol (RIP) configuration commands in
the subscriber record.
1.2 PPP Oversubscription
Ordinarily, any bind authentication command causes the subscriber’s
session to be counted toward the maximum number of PPP structures
allocated (which depends on your router and configuration), whether or not the
subscriber is active. The alternative is to configure the system to operate so
that only active PPP sessions count toward the maximum number of structures
allocated. The effect is that the number of bind authentications you can have
is increased, beyond the number that could actually bind and come up (PPP
oversubscription).
Oversubscription does not affect the maximum number of subscribers that
can be terminated in a particular context (established by the aaa max
subscribers
command in context configuration mode) or the hard limits
allowed by the SmartEdge OS.
You configure PPP oversubscription using ppp auto encapsulation in the atm
pvc
(or its atm pvc explicit form) command (in ATM OC configuration
mode). For a complete description of both forms, see the document,
Configuring Circuits.
1.3 Single-Stack and Dual-Stack Support
PPP subscriber and non-subscriber circuits can be single-stack or dual-stack.
Single-stack circuits exclusively support one type of traffic (IPv4 or
IPv6). Dual-stack circuits are authorized for both IPv4 and IPv6, and can
simultaneously support both IPv4 and IPv6 traffic.
Dual-stack non-subscribers must be configured to support both IPv4 and IPv6
traffic.
Note: Although dual-stack subscriber and non-subscriber circuits can
simultaneously support both IPv4 and IPv6 traffic, it is not necessary
for both stacks to be active at the same time.
Dual-stack subscribers use IPCP for IPv4 address negotiation and IPv6CP for
IPv6 address negotiation. IPCP and IPv6CP are independent of one another; if
IPv6CP fails, IPCP still operates and vice-versa. For details on configuring the
router to support IPv6 or dual-stack subscriber services, see Configuring IPv6
Subscriber Services.
3 64/1543-CRA 119 1170/1 Uen K | 2012-12-04