ZyXEL Omni TA 128 User Guide - Page 54

Bandwidth On Demand (BOD) The function of bandwidth on demand (BOD) will monitor the traffic on ISDN links while Multilink PPP. If there is light traffic on the link, one of the channels will be dropped automatically. On the other hand, if only one B channel is used and data traffic is high enough, BOD will establish the second B channel to increase the bandwidth of the data link. The wait for the second B channel's carrier is 60 seconds. If the second B channel can't be connected successfully the BOD will try again after 60 seconds. If the second call is connected but negotiation failed, it will be retry three times. If a connection is not established after the third try the Multilink PPP will be disabled automatically. For BOD, there are four parameters to set high/low threshold and persist time. Traffic utilization is measured in the ISDN link. Highly compressible data may not generate enough traffic to start the second B channel. Both add persist time and subtract persist time must be set to activate BOD. Related commands: • ATJAn - Add traffic threshold for n K bits per second, n = 48 (default). • ATJSn - Subtract traffic threshold for n K bits per second, n = 32 (default). • ATKAmn - Add persist time for n period in m unit, n = 0 - 127, m = s for seconds and m for minutes. • ATKSmn - Subtract persist time for n period in m unit, n = 0 127, m = s for seconds and m for minutes. BACP/BAP Bandwidth Allocation Control Protocol and Bandwidth Allocation Protocol is used for call request and link drop under Multilink PPP. BACP is negotiated during the network phase. Without BACP/BAP, the directory numbers of both B channels must be 42