Draytek Vigor2950 Series User Manual page 118

Bandwidth-On-Demand
(BOD) Setup
114
single B channel, two B channels or BOD (Bandwidth on
Demand). Four options are available: Link Disable, Dialup
64Kbps, Dialup 128Kbps, Dialup BOD.
PPP Authentication - It specifies the PPP authentication
method for PPP/MP connections. Normally you can set it to
PAP/CHAP for better compatibility.
TCP Header Compression - VJ Compression: It is used for
TCP/IP protocol header compression. Normally it is set to Yes
to improve bandwidth utilization.
Idle Timeout - Because our IDSN link type is Dial On
Demand, the connection will be initiated only when needed.
Bandwidth-On-Demand is for Multiple-Link PPP \(ML-PPP
or MP). The parameters are only applied when you set the
Link Type to Dialup BOD. The ISDN usually use one B
channel to access the Internet or remote network when you
choose the Dialup BOD link type. The router will use the
parameters here to decide on when you activate/drop the
additional B channel. Note that cps (characters-per-second)
measures the total link utilization.
High Water Mark and High Water Time - These
parameters specify the situation in which the second channel
will be activated. With the first connected channel, if its
utilization exceeds the High Water Mark and such a channel
is being used over the High Water Time, the additional
channel will be activated. Thus, the total link speed will be
128kbps (two B channels).
Low Water Mark and Low Water Time - These parameters
specify the situation in which the second channel will be
dropped. In terms of the two B channels, if their utilization is
under the Low Water Mark and these two channels are being
used over the High Water Time, the additional channel will be
dropped. As a result, the total link speed will be 64kbps (one
B channel).
Vigor2950 Series User's Guide