R0106-HP MSR Router Series Layer 2 - WAN Command Reference(V7)

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Usage guidelines
Typically, B-channel selection is done by the service provider switch. To improve call establishment
efficiency and reduce call losses on ISDN lines, you can enable the ISDN interface to select B-channels
for calls. This is particularly true for PRI ISDN lines.
• If non-exclusive B-channel selection is enabled, the interface selects a preferred B-channel for a call.
However, it will use the B-channel selected by the peer end when a selection conflict occurs.
• If exclusive B-channel selection is enabled, the interface selects a preferred B-channel for a call. It
does not accept the B-channel selected by the peer end when a selection conflict occurs.
IMPORTANT:
Configure exclusive B-channel selection only when the interface is in network mode. In user mode,
exclusive B-channel selection will cause a call establishment failure when a B-channel selection conflict
occurs.
Examples
# Enable non-exclusive B-channel selection on BRI 2/4/0.
<Sysname> system-view
[Sysname] interface bri 2/4/0
[Sysname-Bri2/4/0] isdn bch-local-manage
isdn bch-select-way
Use isdn bch-select-way to set a B-channel selection method.
Use undo isdn bch-select-way to restore the default.
Syntax
isdn bch-select-way { ascending | descending }
undo isdn bch-select-way
Default
The device selects B channels in ascending order of channel IDs.
Views
ISDN interface view
Predefined user roles
network-admin
Parameters
ascending: Selects ISDN B channels in ascending order of channel IDs.
descending: Selects ISDN B channels in descending order of channel IDs.
Usage guidelines
If the interface is operating in user mode, this command takes effect only when the isdn
bch-local-manage command is configured.
Examples
# Set the B channel selection method to descending order on BRI 2/4/0.
<Sysname> system-view