Call-By-Call Service Selection - Nortel BCM50 Configuration Manual

108 Chapter 9 Configuring telephony resources
The ISDN setting requires digital access lines (DAL) that have digital network loss treatment. On
a DAL network, the PBX system administers the dB loss, not the CO. DALs may have ISDN
signaling or digital signaling (for example, T1). The loss plan follows the Draft TIA-464-C loss
plan, which uses a send loudness rating (SLR) of 8 dB. You must contact your service provider to
get DAL network loss treatment on a line with digital signaling.
The PSTN setting requires analog access lines (AAL) that have analog network loss treatment and
digital signaling. On an AAL(D) network, the CO administers the dB loss.
The loss plan follows the Draft TIA-464-C loss plan. The ISDN loss plan uses a send loudness
rating (SLR) of 8 dB and a receive loudness rating (RLR) of 2 dB. The PSTN loss plan uses an
SLR of 11 dB and an RLR of -3 dB. If you choose the wrong setting, the voice signal can be too
loud or too soft.
Internal CSU
Internal CSU allows you to turn the internal T1 channel service unit on or off. The channel service
unit gathers performance statistics for your T1 lines or PRI with public interface. Contact your
service provider for the correct settings.
You can view the performance statistics for your T1 lines in Maintenance under the CSU stats
heading. Before you set the internal CSU to off, you must ensure there is an external CSU
connected to your T1 lines.

Call-by-Call Service Selection

This following provides information about how to configure the PRI Call-by-call Service
Selection, which is region-specific to North America, for a DTM set to a PRI Module type.
By default, incoming calls on a PRI are routed based on the Called Party Number information
within the call request. The last number of digits of the called party number that match the
Received Number Length setting are used as Receive Digits to find a target line.
In North American PRI, the Call-by-Call services allows alternate routing maps to be defined in
various ways, depending on the protocol defined for this PRI.
NN40020-603 NN40020-603