ADTRAN L128 - Manual (Page 30)

Chapter 1: Understanding ISDN and the Express L128/L128T
61202.070L1-1 Express L128/L128T User Manual 13
Bridging
In Bridge Mode, the Express L128/L128T can communicate with two remote
networks at a time. The destination is dialed by setting up a Connection List
profile and choosing Dial on the Dial menu. See Configuration/Connection List
on page 63 for instructions on setting up a Connection List profile.
During a two B-channel PPP Multilink call, the Express L128T automatically
drops one B-channel and provides it to the POTS port when a telephone call is
placed or answered. When a POTS telephone call terminates, the Express L128
redials the second B-channel and supplies the bandwidth back to the LAN
connection. Since other bandwidth management 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 se-
lected remote network.
The Connection List described in the next section may be used to automate di-
aling and to store additional information specific to the remote site being di-
aled (phone numbers, number of B-channels to dial, authentication
information, Caller ID, etc.). In addition, to reduce line charges, Demand Di-
aling 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]/Bandwidth/On De-
mand
option on the Connection List. Setting this parameter to a non-zero val-
ue 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 L128/L128T’s advanced filtering capability. When new traf-
fic needs to be transmitted, the Express L128/L128T 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 ad-
dition, when both B-channels 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.