Bridging - ADTRAN Express 4100 User Manual

Chapter 1. Understanding ISDN and the Express 4100/4110

Bridging

In Bridge Mode, the Express 4100/4110 can communicate with two
remote networks at a time. The destination is dialed by setting up a Con-
nection List profile and choosing Dial on the Dial menu. See "Configura-
tion/Connection List" on page 3-36 for instructions on setting up a
Connection List profile.
During a two B-channel PPP Multilink call, the Express 4110 automati-
cally drops one B-channel and provides it to the POTS port when a tele-
phone call is placed or answered. When a POTS telephone call
terminates, the Express 4100 redials the second B-channel and supplies
the bandwidth back to the LAN connection. Since other bandwidth man-
agement features are disabled in the factory default configuration, the
dialed links remain active until the Hang-up command is entered from
the Dial menu, terminating the session with the selected remote network.
The Connection List described in the next section may be used to auto-
mate dialing and to store additional information specific to the remote
site being dialed (phone numbers, number of B-channels to dial, authen-
tication information, Caller ID, etc.). In addition, to reduce line charges,
Demand Dialing may be enabled to allow idle links to disconnect when
not being used .
Simple Demand Bridging may be configured by enabling the Idle Time-
Out parameter under the Configuration/ Connection List [1]/Band-
width/On Demand option on the Connection List. Setting this parame-
ter to a non-zero value allows a bridge connection to disconnect after the
specified number of seconds with no traffic crossing the ISDN link.
Bandwidth can be controlled using the Express 4100/4110's advanced fil-
tering capability. When new traffic needs to be transmitted, the Express
4100/4110 will run each packet through its Demand filters defined for
each Connection List profile. If a packet can pass through the filter, then
the numbers for that profile are dialed. In addition, when both B-chan-
nels are selected for use, the link may be configured to add/remove the
second B-channel based on the amount of traffic crossing the link. The
bridged connection is terminated when the Hang-up option is selected
from the Dial menu, but will redial if the demand filter condition is met.
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