BelAir20E User Guide
Using Layer 2 Tunnels
April 2, 2012
Confidential
Document Number BDTM02201-A01 Standard
Configuring Tunnel
Advanced Parameters
/protocol/te-<eng>/set tunnel <index> advanced
[l2tp-hello-interval <seconds>]
[l2tp-hello-retrans <number>]
[l2tp-hello-timeout <seconds>]
[ppp-echo-interval <seconds>]
[ppp-echo-retrans <number>]
[dscp-control <hex value>]
The
set tunnel advanced
command lets you specify for particular tunnel timers
and other parameters associated with the L2TP protocol.
The <index> parameter is used for easy reference when using other
commands. It can be displayed with the
/protocol/te-<eng>/show config
command.
The following parameters can be set with this command:
• L2TP Hello transmission interval. Values range from 10 to 300 seconds. The
default setting is 60 seconds.
• L2TP Hello retransmission count. Values range from 1 to 10. The default
setting is 5.
• L2TP Hello retransmission maximum interval. Values range from 1 second
to 32 seconds. The default setting is 8 seconds.
• PPP echo transmission interval. Values range from 0 seconds to
300 seconds. 0 seconds means PPP echo is disabled. The default setting is 10
seconds.
• PPP echo retransmission count. Values range from 1 to 50. The default
setting is 10.
• DSCP value for control (L2TP/PPP) packets. The default setting is 0.
The AP uses the L2TP Hello parameters to determine if the tunnel is available.
If the AP does not receive a Hello packet during the
L2TP Hello transmission
interval
, it begins to send its own Hello packets at exponential intervals starting
at 1 second (that is, at 1, 2, 4, 8, ... seconds) until the
L2TP Hello retransmission
count
and
L2TP Hello retransmission maximum interval
are reached. If not of
the retransmitted Hello packets are answered, then the tunnel is considered
unavailable. For additional details, refer to the L2TP specification.
The PPP echo parameters are also used to determine tunnel availability. PPP
echo packets are sent periodically with the interval specified by the
PPP echo
transmission interval
. The tunnel is considered unavailable if the AP does not
receive consecutive responses for the number of packets specified by the
PPP
echo retransmission count
.