7-20 Feature interaction
297-2521-106 Standard 23.01 March 2001
conditional selectors, the functionality of time-of-day routing is not
modified with the introduction of PRI on the switch.
Trunk group class-of-service screening
Trunk group class-of-service screening is performed to determine whether
the originating and terminating types of trunks are allowed to be connected
to each other based on their class of service. Trunk group class-of-service
screening is performed on all PRI calls, regardless of whether ISA direct
routing is performed.
Retranslation
The DMS-250 switch currently provides the ability to assign an outgoing
route selector as the RX route selector. This means that calls terminating to
that route are capable of retranslating, and choosing another outgoing route.
In retranslations, the following can be specified:
• the STS used when retranslating the call
• a digit manipulation (DIGMAN) index used to add or delete digits from
the called number field prior to retranslations. The new digits are then
pretranslated and translated according to IEC translations.
The pretranslator name used cannot be specified. The source of the
pretranslator name depends on the nature of the retranslated call. For
non-PRI-originated calls, the pretranslator name is taken from table
TRKGRP. For PRI-originated calls, the pretranslator name is taken from
table CALLATTR and from the CALLATTR tuple used on the originating
PRI call.
Satellite screening
Satellite screening prevents the use of more than one satellite hop for a call.
The PRI is not supported over satellite facilities. All PRI agencies
originating on or terminating from the DMS-250 switch must travel over
land-based transmission media. However, if satellite screening is performed
on PRI agencies, the call does not produce an error and satellite screening
passes. (Screening indicates that the PRI is a non-satellite trunk.)
Satellite screening always fails for calls marked as DATA. Any of the
following bearer capabilities always cause satellite screening to prevent a
satellite jump: 56 kbit/s unrestricted, 64 kbit/s unrestricted, 64 kbit/s
restricted, and 3.1 kHz audio.
Identifying voice/data and transmission rate—bearer capability
Bearer capability (BC) (an information element carried in the SETUP
message) indicates whether the call is voice or data and the rate of
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