Eicon Networks DIVA LAN ISDN manual Configuring AO/DI

Chapter Five: Minimizing ISDN Charges Configuring AO/DI 63

Configuring AO/DI

AO/DI lets you maintain a permanent connection to the Internet or a corporate network, without tying up an expensive ISDN B-channel. AO/DI accomplishes this by using the ISDN D-channel to establish a low-bandwidth (9.6 kbps) connection with your ISP or corporate network. When incoming or outgoing traffic exceeds the capabilities of the D-channel, AO/DI automatically invokes one or more B-channels to handle the increased traffic.

Some advantages of AO/DI include:

•Makes maintaining a permanent connection to the Internet more cost effective. With such a connection, remote users can connect with the DIVA LAN ISDN Modem from any remote location that has Internet access. This eliminates the need to dial in via ISDN. (To make the connection permanent you must set the idle timer to 0. See page 59.)

•Ideal solution for connecting to a remote corporate network, because low-bandwidth keep alive traffic can use the D-channel, instead of constantly bringing up a B-channel.

You customize how AO/DI opens and closes B-channels by setting the following parameters.

•Delay for opening the 1st B-channel:Sets the amount of time data traffic on the ISDN D-channel must exceed the specified Threshold value, for AO/DI to bring up the first B-channel.

•Threshold for opening the 1st B-channel:Sets the percentage of total bandwidth on the D-channel that must be exceeded, for AO/DI to bring up the first B-channel.

•Delay for closing the 1st B-channel:Sets the amount of time data traffic on the ISDN D-channel must be below the specified Threshold value, for AO/DI to drop the first B-channel.

•Threshold for closing the 1st B-channel:Sets the percentage of total bandwidth on the D-channel that traffic must be below, for AO/DI to drop the first B-channel.

•Delay for opening the 2nd B-channel:The amount of time data traffic on the first B-channel must exceed the specified Threshold value, for AO/DI to bring up the second B-channel.

•Threshold for opening the 2nd B-channel:Sets the percentage of total bandwidth on the first B-channel that must be exceeded, for AO/DI to bring up the second B-channel.

•Delay for closing the 2nd B-channel:Sets the amount of time data traffic on the first B-channel must be below the specified Threshold value, for AO/DI to drop the second B-channel.

•Threshold for closing the 2nd B-channel:Sets the percentage of total bandwidth on the first B-channel that traffic must be below, for AO/DI to drop the second B-channel.

•Mode: Determines ISDN line usage when AO/DI is enabled.

•D-Channel Only: Data is only transferred on the D-channel.

•Normal: Data is transferred on the D-channel, plus both B-channels if required.

•Dial prefix: Specifies the prefix to dial when making a call. For example, 1 to call long distance, or 9 to obtain an external line

•X.25 transmit queue threshold: Specifies the transmit queue threshold, in bytes, for X.25 on the D-channel. When queued data exceeds this limit, for the period of time specified for the parameter Delay for opening the 1st B-channel, the first B-channel is brought up. This parameter performs a similar function to Threshold for opening the 1st B-channel, and can be used concurrently with that parameter.