Example 2: L2Tp Session Over Ethernet Vlan Interface; Transmit Connect Speed Reporting Considerations; Session Termination For Dynamic Speed Timeout; Advisory Speed Precedence For Vlans Over Bridged Ethernet - Juniper JUNOSE SOFTWARE 11.2.X - BROADBAND ACCESS CONFIGURATION GUIDE 7-20-2010 Configuration Manual

JunosE 11.2.x Broadband Access Configuration Guide

Transmit Connect Speed Reporting Considerations

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Example 2: L2TP Session over Ethernet VLAN Interface

In this example, an L2TP session is established over a PPPoE subinterface over an Ethernet
VLAN subinterface. The configuration has the following characteristics:
The Ethernet VLAN subinterface is configured with an advisory transmit speed of
100 Mbps.
The dynamic layer 2 setting does not apply to the VLAN subinterface.
The transmit connect speed calculated by QoS is 10 Mbps.
Based on these characteristics, Table 71 on page 394 lists the transmit connect speed
value reported in L2TP Transmit (TX) Speed AVP 24 for each calculation method, and
the reason why L2TP reports this value.

Table 71: Transmit Connect Speeds for L2TP over Ethernet Example

Transmit Connect
Calculation Speed Reported in
Method AVP 24
Static layer 2 100 Mbps
Dynamic layer 2 100 Mbps
QoS 10 Mbps
Actual 10 Mbps
The following considerations affect the transmit connect speed value reported in L2TP
Transmit (TX) Speed AVP 24 when you use this feature.

Session Termination for Dynamic Speed Timeout

Under certain heavy load conditions, the router might be unable to obtain the
dynamic-layer2 value for the transmit connect speed of the subscriber's access interface.
In this situation, the LAC sends the LNS an L2TP Call-Disconnect-Notify (CDN) message
to terminate the L2TP session.
For more information about supported L2TP terminate reasons, see "AAA Terminate
Reasons" on page 271.

Advisory Speed Precedence for VLANs over Bridged Ethernet

For interface columns that consist of an L2TP session over an Ethernet VLAN subinterface
over a bridged Ethernet interface, the advisory transmit speed of the VLAN subinterface,
Reason
L2TP reports the advisory transmit speed configured
on the VLAN subinterface. If configured, the advisory
transmit speed takes precedence over the physical
port speed for a VLAN subinterface.
L2TP reports the static layer 2 value because the
dynamic layer 2 setting does not apply to a VLAN
subinterface.
L2TP reports the transmit connect speed calculated
by QoS.
L2TP reports the lesser of the dynamic layer 2 speed
(100 Mbps) or the QoS speed (10 Mbps).
Copyright © 2010, Juniper Networks, Inc.