Working with fractional PRI Installer password required
When you purchase PRI from your service provider, you can request the number of B-channels that are allocated for you to use. For example, you may want to use only 12 B-channels instead of 23 B-channels. If this is your situation, you should disable all the B-channels that you do not need.
It is recommended that the number of lines that are deprovisioned on a DTI card (configured as PRI) be the same as the number of B-channels that are disabled. For example when B-channels 13-23 are disabled, you should deprovision lines 13 to 23.