7-2
Stinger®
IP2000 Configuration Guide
Broadband RAS Configuration
Overview of PPPoA and PPPoE topologies
With the default
call-type
setting of
ft1
in a PPP profile, if {
1 1 1 }
is enabled
(with or without connections), the system generates rolling LOG errors, LOG
warning, and LOG information messages. This condition is prevented by setting
call-
type
to
off
.
In addition, when
call-type
is set to
off
, the system is able to terminate PPP sessions
automatically following a period of client inactivity, and reestablish them when the
client becomes active again.
Overview of PPPoA and PPPoE topologies
A PPPoA connection uses the ATM adaptation layer 5 (AAL5) protocol as a framing
mechanism across point-to-point virtual circuits, as described in RFC 2364, PPP over
AAL5. Only VC-multiplexed PPPoA is currently supported. The PPPoA session is
between the router and the Stinger unit, as shown in Figure 7-1. The PPPoA session
enables an IP client on the far side of the PPPoA router to connect through the
Stinger unit to the IP cloud beyond it.
Figure 7-1. PPPoA topology
For PPPoE, the connection uses Ethernet-bridged framing, as defined in RFC 2516, A
Method for Transmitting PPP Over Ethernet (PPPoE). PPPoE is negotiated in two phases: a
discovery phase and a session phase. During the discovery phase, the PPPoE client
negotiates with the Stinger to obtain information it requires. When the session has
been established, the client sends PPP packets encapsulated in Ethernet-bridged
frames.
The PPPoE sessions shown in Figure 7-2 are between a PPPoE client connected
through the bridge, and the Stinger unit. The PPPoE session enables the client to
connect through the Stinger unit to the IP cloud beyond it.
Figure 7-2. PPPoE topology
Note
Currently, the Stinger IP2000 does not support multiclient PPPoE across a
single DSL interface.
Router
(PPPoA)
IP
ATM
IP
PPPoA
IP client
Stinger IP2000
IP
ATM
Bridge
PPPoE
client
PPPoE
Ethernet
Stinger IP2000
