ZyXEL Communications Prestige 480 - Manual (Page 93)

Prestige 480 Dual BRI ISDN Router
Remote Node Configuration 4-7
Table 4-2 BTR v MTR for BOD
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
BTR = 256, MTR = 256 4 4 On
The Min. Channels and Max. Channels allows you to force the Prestige to use a minimum and
maximum number of channels.
When bandwidth on demand is enabled, a second channel will be brought up if tra ffic on the initial channel is
higher than the high Target Utility for second channel 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.
When the Max. Channels is set to 3 or 4 and the threshold set in the Target Utility is reached for
the second channel a third and fourth channel is opened. The Bandwidth increment for
Additional Channels specifies the line utilization range at which you want the Prestige to add or subtract
the third and fourth channel.
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 30 kbps and subtract threshold is 60 kbps. The Prestige performs
bandwidth on demand only if it initiates the call. Addition and subtraction are based on the values set in the
BOD Calculation field. If this field is set to Transmit or Receive, then traffic in either direction will be
included to determine if a link should be added or dropped. Transmit will only use outgoing traffic to make
this determination and Receive will only use incoming traffic to make this determination.
After making the call to bring up a second channel, if the second channel does not succeed in joining the
Multilink Protocol bundle (because the remote device does not recognize the second call as coming from the
same device), the Prestige will hang up the second call and continue with the first channel alone.
You can do the BOD configuration using Menu 11.2 - Remote Node PPP Options.