ATT DEFINITY Communications System Generic 3 Instructions Manual

Generalized Route Selection (GRS)
Issue  3   March 1996
3-747
The GRS capability will recognize one or more of the following five BCCs for each 
trunk group preference in the routing pattern (DCP/DMI mode is explained later).
:
Table 3-58. BCC Assignment
EndpointVoice/ 
Data Mode BCC Comments
Voice Terminal Voice 0
Data Line Circuit Pack 2 2
Voice Data Set 2 2
Modular Processor 
Data Module0,1,2 1,2,4 See Note
Modular Processor
Data Mo dule-M11 1 For ACCUNET Switched 
56 kbps Service
Modular Trunk 
Data...

Feature Descriptions
3-748Issue  3   March 1996 
NOTE:
For all endpoints, the switch automatically determines its current operating 
mode when the data mo dule originates.  Before any call is originated, the 
default is Mode 2.
Since call origination from a data mo dule d etermines the mo de to be used 
on the call, it is recommended that the data module user press the 
Originate/Disconnect button once after changing data options. This way, 
the right mo de is sure to be assigned to the next call....

Generalized Route Selection (GRS)
Issue  3   March 1996
3-749
More than one Information Transfer Capability can be supported by one BCC. 
Low-Layer Compatibility
The low-layer comp atibility information element provides remote compatibility 
checking. This element is used with the bearer capability element and 
determines the mode of the originating caller. The low-layer compatibility 
information element is optional and sent only in case of data calls.
NOTE:
DCP Mode 0 does not send  an LLC IE.
DCP/DMI...

Feature Descriptions
3-750Issue  3   March 1996 
Determination of BCC at Tandeming or 
Terminating System
Determination of the BCC for an incoming call from a ISDN-PRI trunk to a tandem 
or terminating switch is based on the BCC parameters received on the signaling 
channel (D-channel) of the trunk. This includes the ITC (restricted or unrestricted) 
if the call is a data call.
Determination of the BCC for an incoming call from a non-PRI trunk will be as 
follows:
nIf the incoming trunk is a voice trunk,...

Generalized Route Selection (GRS)
Issue  3   March 1996
3-751
A BCC 0 originated call (such as voice or analog modem) will not b e 
denied routing by GRS, even if the routing pattern lacks a preference with 
BCC 0 set to yes. This allows the user to use voice transfer to data when 
making a data call, without the need for data preindication.
If a BCC 0 originated  call accesses a routing pattern for which no 
preference has BCC 0 set to yes, then GRS will choose a preference with 
BCC 2 set to yes, if...

Feature Descriptions
3-752Issue  3   March 1996 
BCC information that the far-end receives in the SETUP message will become the 
originating BCC for the far-end’s incoming trunk call.
nIf an exact match of the originator’s BCC and ITC has been found,  then 
that Bearer Cap a bility is encoded and sent in the ISDN SETUP  message 
to the far-end. If the call is a data call, the system uses the ITC of the 
routing p attern to encode the SETUP message as shown in Table 3-61.
nIf an exact match is not found,...

Generalized Route Selection (GRS)
Issue  3   March 1996
3-753
BCC and ITC Determination on Calls from 
Endpoints to ISDN-PRI Trunks
Table 3-62. Calls from Endpoint to ISDN-PRI Trunks
Originating Chosen BCC from the Routing Pattern
BCC BCC 0 BCC 1 BCC 2 BCC 3 BCC 4
BC C 0 P PT PT PT PT
BCC 1 BPBBB
BCC 2 PMBPBB
BCC 3 BBBPB
BCC 4 BBBBP
Legend
B Block the call with intercept treatment
P Allow the call and send the originating en d point’s BCC in the 
SETUP m essage.  Use the ITC as shown in the following...

Feature Descriptions
3-754Issue  3   March 1996 
If BCC 1, 2, 3, or 4 is chosen from the preceding table, the following table is used 
to d etermine the a p propriate ITC.
Table 3-63. Calls from Endpoints to ISDN-PRI Trunks
Originating Chosen ITC from the Routing Pattern
ITC unr rest both endpt both unr
unrPBPPU
restBPPPU
Legend
B Block the call with interc ept treatment
P Allow the call and send the originating endpoint’s ITC in the 
SETUP message
PU Allow the call and send ‘‘unrestricted’’ in the SETUP...

Generalized Route Selection (GRS)
Issue  3   March 1996
3-755
BCC and ITC Determination on Calls from 
Trunks to ISDN-PRI
Table 3-64. Calls from Trunks to ISDN-PRI Trunks
Originating Chosen BCC from the Routing Pattern
BCC BCC 0 BCC 1 BCC 2 BCC 3 BCC 4
B C C  0 P PT PT PT P T
BCC 1 BPBBB
BCC 2 PTBPBB
BCC 3 BBBPB
BCC 4 BBBBP
Legend
B Block the call with interc ept treatment
P Allow the call and send the incoming trunk’s BCC in the 
SETUP message. Use the ITC as shown in the following 
table
PT Allow the...

Feature Descriptions
3-756Issue  3   March 1996 
If BCC 1, 2, 3, or 4 is chosen from the preceding table, the following table is used 
to d etermine the a p propriate ITC.
The system does not insert pooled modem for any interworking 
trunk-to-ISDN-PRI trunk calls. The BCC and ITC of an incoming trunk is 
determined as follows:
nISDN-PRI Trunk BCC and ITC are in the received SETUP m e s sa g e
nAVD Trunk BCC and ITC are the BCC and ITC values administered on the  
trunk group form
nRBAVD Trunk BCC and ITC...