Enabling the R2 Protocol
November 2009 350
Backward Channel
Table 19 identifies the set of backward inter-register signals. The
tones defined are those used to support DNIS and ANI services
appropriate for customer premise equipment. Not all tones that are
possible under the ITU recommendations are required nor
implemented at this time. Certain tones might not be defined in a
particular variant. In such a case, the values of those tones should be
set to R2B_INVALID. In addition, certain signals are normally
expected to have the same absolute signal code whether the forward
channel is in state DNIS or state ANI. For example, this is true for
the congestion signal. However, distinct definitions are provided in
these cases to allow customization for an arbitrary variant.
PROCESS_CONGESTION_SIGNAL Process congestion signal. DNIS or
ANI
PROCESS_NEXT_ANI_DIGIT_REQUEST Process request for next
ANI digit. ANI
PROCESS_CALLING_PARTY_CATEGORY_
REQUEST Process request for
calling party (ANI)
information.
DNIS
PROCESS_CALL_ACCEPTED_NO_GROUP_B Process call accepted
without need for Group B
line condition.
DNIS
PROCESS_NATURE_OF_CIRCUIT_QUERY Process request for circuit
nature. DNIS
PROCESS_ECHO_SUPPRESSOR_QUERY Process request for use of
echo suppressor. DNIS
PROCESS_GROUP_B_LINE_CONDITION Process received
(Group B) called line
condition.
Line
condition
Table 21. IISDN_R2MFC_FORWARD_ACTIONS (Continued)
Name Description State