TW-H6W1IR ISDN Remote Router
Configuration and Management 103
? ? BOD Low Threshold (%) – (0 to 100) The throughput value as a
percentage of total bandwidth which will cause the highest
numbered ISDN port in the MLPPP bundle to hang up, thus
subtracting bandwidth from the connection. Before actually hanging
up however, the throughput must be below this value for the time
designated in the Subtract Bandwidth Delay field.
? ? Add Bandwidth Delay (sec) – (0 to 300) The amount of time in
seconds the router will wait and sample the BOD Criteria before
adding bandwidth once the throughput exceeds the BOD High
Threshold. This prevents costly bandwidth from being
unnecessarily added due to temporary bursts in traffic.
? ? Subtract Bandwidth Delay (sec) – (0 to 300) The amount of
time in seconds the router will wait and sample the BOD Criteria
before subtracting bandwidth once the throughput falls below the
BOD Low Threshold. This prevents bandwidth from being
unnecessarily subtracted due to temporary lulls in traffic.
The example Multi-link PPP settings shown in the Multi-Link PPP
Configuration window above assumes that ISDN 1 and ISDN 2 each
have a 64kbps connection configured to dial up to the Internet. When
ISDN 1 receives a packet destined for the Internet it will dial the ISP
and establish a connection. If the total throughput on ISDN 1 (TX +
RX) ever exceeds 80% of the 64kps (51.2kps), the router will sample
the line for an additional 5 seconds. If the traffic continuously exceeds
80% for the 5 second delay time, ISDN 2 will dial up and add
bandwidth to the connection. Assuming sustained traffic of 70kps,
MLPPP will balance the traffic on the two ISDN ports so they are
handling roughly 35kps each. If the traffic on ISDN 1 + ISDN 2 falls
below 20% of the 128kps connection (25.6kps) for more than 10
