ATT DEFINITY Communications System Generic 3 Instructions Manual

							Facility Test Calls (with Security Measures)
Issue  3   March 1996
3-737
Interactions
None.
Administration
Facility Test Calls is administered on a p er-system basis b y the System Manager.  
The Facility Test Calls access code must be assigned. Also, a user’s Class of 
Restriction must be a dministered with the Facility Access Trunk Test option in 
order for the user to make trunk test calls.
Hardware and Software Requirements
No a d ditional hardware or software is required. 
						

							Feature Descriptions
3-738Issue  3   March 1996 
Facility and Non-Facility Associated 
Signaling
Feature Availability
This optional feature is available with all Generic 3 releases,  except G3vs/G3s 
ABP, when ISDN PRI software is purchased.
Description
Provides signaling for ISDN-PRI.
Facility Associated Signaling
Facility Associated Signaling (FAS) allows an ISDN-PRI DS1/E1 Interfac e
D-channel to carry signaling information for only those B-channels located on the 
same DS1/E1 facility (circuit pack) as the D-channel.
Non-Facility Associated Signaling
Non-Facility Associated Signaling (NFAS) allows an ISDN-PRI DS1/E1 Interface
D-channel (signaling channel) to convey signaling information for B-c hannels 
(voice and data channels) on ISDN-PRI DS1/E1 facilities other than the one 
containing the D-channel. As a result, a D-channel can carry signaling 
information for numerous B-channels located on different DS1/E1 facilities.
NOTE:
NFAS is only valid for DS1/E1 Country Protocol option 1 (U.S.).
D-Channel Backup
To improve reliability in the event of a signaling link failure, a backup D-Channel 
may b e administered. If a signaling link failure does occur, a switch to a backup 
D-channel will then take place.
D-Channel Backup requires that one D-channel be administered as the Primary 
D-channel and that a second D-channel be administered as the Secondary
D-channel. These assignments insure that at certain times d uring D-Channel 
Backup procedures that both D-c hannels are in the same state.  This avoids the 
occurrence of both switches at each end of the DS1/E1 interface selecting the 
same D-channel to be put into service.  In these cases, the Primary D-channel is 
given precedence over the Secondary D-channel. 
						

							Facility and Non-Facility Associated Signaling
Issue  3   March 1996
3-739
Figure 3-16 shows a possible configuration involving three ISDN-PRIs b etween a 
G3 switch and another DEFI NIT Y syst em  or the  public network. With  DS1  (24 
channel) interfaces, two of the ISDN-PRIs contain a D-channel and 23 
B-c hannels, while the other ISDN-PRI contains 24 B-channels.  One of the 
D-channels is the Primary D-channel, and the other is the Secondary D-channel.  
Together, this p air of D-c hannels will signal for all 70 (23+24+23) of the 
B-c hannels that are part of the three PRIs.
Since the D-channels are signaling for more than one DS1/E1 facility, the 
D-channel Ba ckup feature requires the use of the NFAS feature.  At any given 
time, one of the two D-channels will be carrying Layer 3 signaling messages, 
while the other D-channel will be active at layer 2, but in a stan d by mode only. 
Any layer 3 messages received over the standby D-channel will b e ignored. 
Since only one of the D-channels can be active at a time, load sharing between 
the two D-channels is not possible.  The two D-channels can provide signaling 
for only a predefined set of B-channels and cannot dynamically back up other 
D-channels on other interfaces.
Figure 3-16. Example D-Channel Backup With Three ISDN-PRIs
D-Channel Backup Activation. D-Channel Backup can be invoked in response 
to the following events:
nD-Channel Failure
If the signaling link fails on the active D-channel (D1) or the hardware 
carrying D1 fails, then the system will send a message over the standby 
D-channel (D2), which requests that D2 become the active D-channel. D2 
then b ecomes the active D-channel and will c arry all subsequent signaling 
messages.  When the signaling link or hard ware on D1 recovers from the 
failure, D1 becomes the standby D-channel.
ISDN PRIMARY RATE INTERFACES CONTROLLED BY D-CHANNEL
PRIMARY D-CHANNEL
FAR-END
SWITCH NETWORK
OR
SWITCH
DEFINITY
SECONDARY D-CHANNEL
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							Feature Descriptions
3-740Issue  3   March 1996 
nSystem Technician Commands
If a system technician command requests that a D-channel switch-over 
take place, the first action taken by the system will b e to tear down the 
signaling link on D1.  After this has b een completed, a message is sent on 
D2 to request that D2 become the active D-channel. D2 then b ecomes the 
active D-channel and the switch-over will be complete.
Considerations
NFAS allows a single D-channel to carry signaling information for numerous 
B- channels located on different DS1/E1 facilities, thus providing a more 
economical interface.
Only those ISDN-PRI facilities that use the NFAS feature will be c a pable of 
providing the D-Channel Backup feature.  The reason for this limitation is that the 
two D-channels must be located on different PRI DS1/E1 facilities.  As a result, 
the D-channels must su pp ort NFAS so that they can signal for B-channels on 
different ISDN-PRI DS1/E1 facilities.
When a transition from one D-channel to another occurs (D-Channel Backup is 
activated), all stable calls (calls that have been answered already) will b e 
preserved. Some messages may be lost, resulting in a loss of call-related 
information, but the calls themselves will be maintained.  The effect of the 
transition on unstable calls (those that have not been answered yet) is 
unpredictable since the results depend on which messages were lost and the 
contents of those messages.
Interactions
None.
Administration
The following provisioning and administration must be considered when 
implementing FAS and NFAS.  Coordinate the following with the far-end switch 
for the DS1/E1 facilities to be used:
nDecide which DS1/E1 facilities will use FAS.
nDecide which of the remaining DS1/E1 facilities will carry D-channel 
signaling information on the 16th (E1) or 24th (DS1) channel.  For those 
channels that have a D-Channel Backup, D-channel pairs must be 
allocated.
nDefine Signaling Groups. A Signaling Group is a group of B-channels for 
which a given D-channel (or D-channel p air) will carry the signaling 
information. Each Signaling Group must be designated as either a FAS or 
NFAS Signaling Group. 
						

							Facility and Non-Facility Associated Signaling
Issue  3   March 1996
3-741
— A FAS Signaling Group must contain all the ISDN B-Channels on 
the DS1/E1 interface associated with the group’s D-channel, and 
cannot contain B-channels from any other DS1/E1 circuit pack. For 
24-channel DS1 b oards, some of the DS1 ports may use in-band 
(rob bed-bit) signaling and be members in a tie trunk group rather 
than an ISDN trunk group. These tie trunks cannot be members of a 
Signaling Group.
— There is no restriction on which DS1/E1 ports can belong to an 
NFAS Signaling Group. Normally, an NFAS Signaling Group 
consists of one or two D-channels and several complete DS1/E1 
interfaces.
If a Signaling Group contains only a subset of a DS1/E1’s 
B-c hannels (ports 1 through 12, for example), it is considered an 
NFAS Signaling Group, not a FAS Signaling Group. The remaining  
B-c hannels on the DS1/E1 will then be assigned as members of 
another NFAS Signaling Group.
nAn Interface ID must  be assigned to each DS1/E1 facility in an NFAS 
Signaling Group.  For examp le, if the B-channels in a Signaling Group 
span three DS1/E1 facilities, a unique Interface ID must b e assigned to 
each of the three DS1/E1 facilities. This d esignation is required to uniquely 
identify the same B-channel (port) number on each of the DS1/E1 facilities 
in the signaling group. Therefore, this designation must be agreed upon 
by both sides of the interface and administered prior to initialization.
nD-Channel Backup involves two or more ISDN-PRI DS1/E1 facilities that 
interconnect the switch to another PBX or to the network.  Two D-channels 
must  be present on the facilities.  One of the D-channels is designated as 
Primary and the other as Secondary.  This designation must be agreed 
upon by both sides of the interface and administered prior to initialization.
Hardware and Software Requirements
See the Integrated Services Digital Network (ISDN) — Primary Rate Interfac e 
feature for hardware and software requirements. 
						

							Feature Descriptions
3-742Issue  3   March 1996 
Flexible Billing
Feature Availability
Available with G3V4 a n d later releases. Flexible Billing is available in the United 
States for use with AT&T MultiQuest® 900 Vari-A-BillTM Service.
Description
With Flexible Billing the DEFINITY  switch or an a djunct can communicate with the 
AT&T network through ISDN PRI messages to change the rate at which an 
incoming 900-type call is billed. Rate change requests can b e made anytime 
after the call is answered and before it disconnects.
To administer Flexible Billing, the Flexible Billing and ISDN-PRI fields on the 
System-Parameters Customer-Options form must b e set to yes. Only an AT&T 
authorized representative can administer the System-Parameters 
Customer-Options form. You can display the form by entering the display 
system-parameters customer-options command.
All change requests are initiated b y an Adjunct Processor (CPE  Ho st or VRU) 
connected to the DEFINITY switch. The  Adjunct Processor determines when to 
request a rate change based on information from customer-provided software 
residing on the processor.
The billing rate can be changed to any of the following:
nNew Rate
nFlat Rate (not d ependent on length of call)
nPremium Charge (a flat charge in addition to the existing rate)
nPremium Credit (a flat negative charge in addition to the existing rate)
nFree Call
There is never a negative charge for calls. A maximum is set for each 900 
number as part of the provisioning process.
NOTE:
It is the responsibility of the customer to notify callers of rate changes. 
Before instructing the network to change the caller rate, the customer must 
inform the caller of the new rate and gain confirmation of the rate from the 
caller. 
						

							Flexible Billin g
Issue  3   March 1996
3-743
Applications
The following list gives examples of when a customer might decide to change the 
rate for a call that is in progress:
nA new rate mi ght b e established for higher valued services such as 
requests for particularly valuable information, conversion of text mail to 
speech, or technical support.
nA flat rate might be desired for consultative support, warranty registration, 
maintenance contracts or for the recovery of a fixed-cost service or 
product.
nA premium charge could be requested for callers who need specialized 
delivery of information such as overnight mail or FAX, recovery of the cost 
of a sample product, an account summary, or a transcript.
nA Premium Credit might be appropriate for promotional discounts, 
first-time callers, contest winners or those who use low overhead 
resources such as electronic me dia rather than human agents.
Detailed Operation
An incoming PRI  call from the network contains messaging that indicates if the 
call can use the AT&T MultiQuest®  900 Vari-A-BillSM Service. This information is 
passed to the Adjunct Processor using ASAI messaging or to the PRI VRU 
adjunct. The Adjunct Processor will only be informe d of the Flexible Billing 
capability of a call if the called VDN, split or agent is included in a domain for 
which notification has been requested by that Adjunct Processor (monitored 
domain).
The Adjunct Processor can initiate a rate change request message any time after 
the call has been answered and before the call disconnects. The rate change 
request specifies the new billing rate.
The DEFI NI TY switch can handle a limited number of change requests. See 
Appendix A, System Parameters for capacities information. If the switch cannot 
accept a change request, it notifies the Adjunct Processor.  Any success or 
failure resulting from the request is returned to the adjunct.
Subsequent requests c an b e ma de for a call that has already had a rate change. 
In this case:
nIf the original and subsequent requests were “flat charge” or if both were 
“new rate”, the previous change is overwritten. The new rate is effective 
from the time the original change took effect.
nIf the original request was “premium charge” or “premium credit” the 
subsequent request must be either “premium charge” or “ premium 
credit”. The  previous change is overwritten. The new rate is effective from 
the time the original change took effect. 
						

							Feature Descriptions
3-744Issue  3   March 1996 
Considerations
Cellular End Offices and some other End Offices (NPA-NXX )  d o not have the 
necessary billing software to accept rate changes. Customers who receive a 
large percentage of calls from specific exchanges, g eographical areas or 
cellular callers should do a careful analysis before using Flexible  Billing.
Interactions
nCall Detail Recording (CDR)
If the User Data item is being recorded, the count for this item will increase 
when Flexible Billing is used.
nCall Vectorin g
Incoming Flexible Billing calls can use Call Vectoring for routing.
If  a VDN R eturn Destination is assigned, and Flexible Billing is active for a 
call, the return destination is ignored and the call is forced to disconnect.
nConference
If a call arriving on a trunk that supports Flexible Billing is conferenced 
with a call from a trunk that does not support Flexible Billing, the switch 
sends billing change requests to the ap propriate trunk. However, if calls 
are conferenced from different trunks that support Flexible  Billing,  only 
one trunk will be sent billing c hange requests.Therefore, never c onference 
calls from two or more incoming Flexible Billing trunks.
nTransfer
If a call is answered by a party on the local switch and is transferred to a 
second switch, the second switch will not receive an indication that the 
call has variable billing. However, Flexible Billing will be available when a 
call is transferred to another monitored domain on the same switch.
Administration
Flexible Billing must be enabled on the Customer-Options System Parameters 
form. In ad dition, ISDN-PRI must  be enabled.
Hardware and Software Requirements
Flexible Billing requires an ASAI Adjunct Processor and customer-supplied 
application software. 
						

							Generalized Route Selection (GRS)
Issue  3   March 1996
3-745
Generalized Route Selection (GRS)
Feature Availability
This optional feature is available when ISDN PRI software is purchased with all 
Generic 3 releases, except G3vs/G3s ABP. Generalized Route Selection is not 
available with G3vs/G3s ABP.
Description
Generalized Route Selection (GRS) provides the customer voice and  data call 
routing c a pabilities to select not only least cost routing,  b ut also optimal routing 
over the a p propriate facilities.
GRS is a cap a bility built on the current Automatic Alternate Routing  (AAR) and 
Automatic Route Selection (ARS) features.   In AAR or ARS, routing is based on 
the dialed number, the Facility Restriction Level (FRL)  of the call originator, the 
partitioning group number, and the time-of-day. By providing additional 
parameters in the routing decision, GRS enhances AAR  and ARS and maximizes 
the  chance of using the right facility to route the call. Also, if an endpoint 
incomp atibility exists, it provides a conversion resource (such as Modem Pools) 
to attempt to match the right  facility with the right endpoint.
GRS allows customers to use separate routes for voice and data calls.   For data 
calls, GRS enables the switch to distinguish between restricted and unrestricted 
digital transmissions, allowing the switch to route data calls onto the a p propriate 
facilities. GRS also provides the op portunity to inte grate voice and data on the 
same trunk group, thereby providing certain economies.
GRS allows the system to use the Integrated Services  Digital Network — Primary 
Rate Interface (ISDN-PRI) call-by-call selection of public network services.   It 
also provides interworking between ISDN-PRI and non-ISDN-PRI entities.
ISDN-PRI interworking is the mixture of ISDN-PRI trunks and non-ISDN-PRI trunks 
in a call.  A mixture of these signaling procedures is required to provide 
end-to-end connectivity when different type trunking facilities are used.
ISDN-PRI services  add  five  additional routing parameters which are specified on 
each trunk group preference of the routing pattern.  These parameters are:
nBearer Capability Class (BCC) 
Id entifies the type of call, such as voice calls and different typ e data calls.
nInformation Transfer Capability (ITC)
Id entifies the type of data transmission (restricte d, unrestricted, or both).
nNetwork Specific Facility 
Id entifies the services and features to b e used to complete a call. 
						

							Feature Descriptions
3-746Issue  3   March 1996 
nBand 
Id ent ifi es t he OUTW A TS  b a n d .  W i d e  Are a Telecommunications Service 
(WATS) is a voice-g rade service providing both voice and low speed data 
transmission calls to defined areas (bands) for a flat rate charge.
nInter-Exchange Carrier (IXC) 
Id entifies the specific common carrier, such as AT&T, to be used for a c all.
In GRS, there are five Bearer Capability Classes (BCCs).  Customers may specify 
routing for each BCC according to their particular transmission needs.
Bearer Capability Classes (BCCs)
The BCCs are the mechanisms by which specialized routing is provided for the 
various type data calls and voice calls. Each trunk g roup preference in the 
AAR/ARS routing p atterns c ontains a BCC p arameter.   When a call is originated, 
a route is selected based on the BCC of the originating facility. BCCs are used to 
classify the type of traffic permitted on this trunk in the outgoing d irection. Details 
on how a trunk group preference is determined are given in the GRS Operation 
section of this description.
A set of ISDN-PRI bearer capability and low-layer compatibility  parameters are 
defined by a BCC. 
The system will determine the originating en d point’s BCC from one of the 
following:
nFor an ISDN-BRI set, the switch determines the BCC by using information 
from the Bearer Capability Information Element (IE)  and Low Layer 
Compati bility IE of the ISDN SETUP  message.
nFor a non-BRI terminal, the switch creates a BCC by using information 
about the station administration for the terminal  and information obtained 
by performing a terminal query.
nFrom the administered value of the incoming trunk. For a non-ISDN trunk 
group, the switch creates a BCC by using the administered BCC value. 
nFrom the ISDN-PRI b earer capability and low-layer compatibility 
parameters, if the  call is an ISDN-PRI trunk-originated call.
The BCC associated with the routing preference in the routing pattern is 
administered by the system administrator. More than one BCC can be 
associated with each preference and the same facility c an ap p ear multi ple times 
in a routing pattern and in multiple routing patterns.
The BCC of the originating en d point (trunk or terminal) is matched with the BCCs 
of the routing preferences. An exact match is not always required. The system 
determines when conversion/insertion resources must be used to successfully 
complete a call via a compatible, but not identical, BCC.