ZyXEL Communications Prestige 100, User Manual

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Remote Node Configuration 55
Bandwidth on Demand
The Bandwidth on Demand (BOD) feature allows you to bundle
both B channels in one logical connection. The second channel is
added and subtracted dynamically according to traffic demand.
The Prestige uses the Bandwidth Allocation Control Protocol
(BACP) and the Multilink Protocol (MP) in implementing
bandwidth on demand.
The configuration of bandwidth on demand focuses on the Base
Transmission Rate (BTR) and the Max. Transmission Rate (MTR).
The relationship between BTR and MTR are shown below:
BTR & MTR Setting No. of
channel(s) used Max No. of
channel(s) used Bandwidth
on demand
BTR = 64, MTR = 64 1 1 Off
BTR = 64, MTR = 128 1 2 On
BTR = 128, MTR = 128 2 2 Off
When bandwidth on demand is enabled, a second channel will be
brought up if traffic on the initial channel is higher than the high
Target Utility number for longer than the specified Add Persist
value. Similarly, the second channel will be dropped if the traffic
level falls below the low Target Utility number for longer than the
Subtract Persist value.
The Target Utility specifies the line utilization range at which you
want the Prestige to add or subtract bandwidth. The range is 30 to
64 kbps (kilobits per second). The parameters are separated by a ‘-
’. For example, ‘30-60’ means the add threshold is 60 kbps and
subtract threshold is 30 kbps. The Prestige will perform bandwidth
on demand only if it initiates the call. Addition and subtraction are
based on the value set in the BOD Calculation field. If this field is
set to ‘Transmit or Receive’, then traffic in either direction will be
calculated to determine if a link should be added or dropped.
‘Transmit’ will only use outgoing traffic to make this