14 Remote Gateway 9150 Installation and Administration GuideRemote Gateway 9150 description Standard 4.064K (56K) dynamic adaptationWith some carriers, 64K calls routed over a 56K PSTN infrastructure may causeerrors. The dynamic adaptation feature allows the Remote Gateway 9150 unitand the RLC to dynamically detect the limitation of the bandwidth. The call isthen downgraded from 64K to 56K.Bandwidth allocationThe RLC automatically allocates trunk bandwidth to the Remote Gateway 9150connection as needed. For example, as calls are initiated and bandwidthrequirements increase, additional trunk connections are established. Likewise, ascalls terminate and bandwidth requirements drop, connections to idle trunks areterminated.Connection typesThe Remote Gateway 9150 connection to the RLC can be defined on the RLC aspermanent or on demand. A permanent connection means that the ISDNconnection to the host PBX always remains open. An on demand connectionmeans that the ISDN connection is established only when a connection with thehost PBX is required.If the connection is defined as demand, then you can configure minimum callduration and idle timers on the RLC to help reduce call charges.Minimum call duration timerMost ISDN tariffs specify minimum charges incurred when you open the line,regardless of the call duration. This charge is the minimum call charge listed onlong distance telephone bills.The minimum call duration timer is used in PSTN mode only and specifies theminimum length of time that each PSTN call to the host PBX remains active,regardless of telephone activity or inactivity. Configure the timer on the RLC todrop inactive connections just before an additional charge period is incurred. Forexample, if the timer is set to 59 seconds and your call lasts only 20 seconds, theISDN connection drops when the timer reaches 59 seconds.
