Draytek Vigor2820 Series User Manual page 218

Bandwidth-On-Demand
(BOD) Setup
Vigor2820 Series User's Guide
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).
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