Lucent Technologies DEFINITY Enterprise Communications Server Release 8.2 Administration For Network Connectivity Manual

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QSIG Basic Call Setup
Transit Counter 
(ANF–TC) DEFINITY ECS provides QSIG ANF-TC as defined in ISO/IEC 6B032 and 6B033. 
It prevents indefinite looping, connections giving poor transmission performance, and 
inefficient use of network resources.
ANF-TC is invoked automatically for ISDN basic calls and the Route Pattern form 
indicates the number of switches through which a call may be routed.
QSIG Basic Supplementary Services
Called/Busy NameEnables the calling party to see the name of the called party at the following times:
•while the call is ringing at the called party’s terminal. 
•while listening to a busy tone because the called party’s terminal was busy. 
Called/Busy Name is similar to the display provided for local on-switch calls, as well 
as for the DCS calls, with the following exceptions:
•Names longer than 15 characters are truncated; only the first 15 characters display.
•The number does not display unless QSIG VALU is enabled.
QSIG Name and 
Number IdentificationQSIG Name and Number Identification allows a switch to send and receive the 
calling number, calling name, connected number, and connected name. QSIG Name 
and Number Identification displays up to 15 characters for the calling and connected 
name and up to 15 digits for the calling and connected number across ISDN 
interfaces.
You can administer outgoing calls as “yes”, “no”, or “restricted.” Restricted means 
that DEFINITY ECS sends the information but sends it “presentation restricted,” 
which indicates to the receiving switch that the information should not be displayed. 
A received restricted number is included on the Call Detail Record (CDR).
Transit switch information
When DEFINITY ECS acts as a transit switch, the QSIG standards require it to pass 
on all supplementary service information that is not addressed to it. This includes 
name information. (A “transit” switch is a switch that routes an incoming call 
administered for Supplementary Services Protocol Bto a trunk also administered for 
Supplementary Services Protocol B.) However, Basic Call Setup and number 
information is subject to modification by the transit switch. This means that trunk 
group administration on a transit switch does not override incoming name 
information, but may override incoming number information (as long as this does not 
lower the restriction on the information).
Example
If a non-restricted calling name and number are received by a DEFINITY ECS acting 
as a transit switch, and if the outgoing trunk is administered for presentation restricted 
for both name and number, the number is passed on as “restricted” and name is 
passed on as “unrestricted.” 
						

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Tandem switch information
However, in the case of tandemed calls (calls involving two ISDN trunks that are not 
both administered for Supplementary Service Protocol B), trunk group administration 
may override both incoming name and number information, as long as doing so does 
not lower the restriction on the information. For example, a tandemed call that comes 
in with restricted name information is sent out with restricted name information even 
if the outgoing trunk is administered for presentation unrestricted. However, 
non-restricted data is sent restricted if the trunk group administration is set for 
“presentation restricted.”
ISDN numbering formats
Numbering is specified on the ISDN Public-Unknown-Numbering and/or ISDN 
Private-Numbering forms. The numbering form you use depends on how you 
administer the ISDN trunk group Numbering Format field.
However, if you format the Called Party Number with public numbering, the 
Calling/Connected Party Number is created in the public format even if you specify 
“private” on the ISDN trunk group form. This provides the caller or called party a 
number that can be used to reach the other party. Since the call routes through the 
public network, the public Calling/Connected Party Number is a more accurate 
address.
Call Forwarding 
(Diversion) Call Forwarding works over a QSIG network. 
When a call has already been forwarded 3 times over a QSIG trunk, it is not 
forwarded again but instead terminates at the final forwarded-to terminal. Remote 
activation and deactivation of this feature are not supported.
Call TransferQSIG Call Transfer is based on the current DEFINITY ECS Transfer and 
Trunk-to-Trunk Transfer features. QSIG Transfer signaling occurs as long as one of 
the calls involves a QSIG trunk between the two switches.
Once a call is transferred, the transferring switch is unnecessary. Additional Network 
Feature-Path Replacement (ANF-PR) is invoked automatically to connect the 
transferred call more efficiently in the private network. QSIG Call Transfer attempts 
to connect the two parties more efficiently and drops the unnecessary switches. 
When you use this feature, you see no difference between QSIG Call Transfer and the 
standard DEFINITY ECS Transfer or Trunk-to-Trunk Transfer features. 
QSIG Call Transfer differs from DCS Call Transfer in that additional call information 
is available for the connected parties after the transfer completes.
Depending upon QSIG Identification Services administration, the connected parties’ 
displays show each other’s name and/or number. If the name and number are not 
available, the display of a connected party updates with the name of the involved 
trunk group. 
						

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Call OfferThis feature is the QSIG equivalent of Call Waiting. 
A Private Telecommunication Network (PTN) offers up to four ways of invoking 
QSIG Supplementary Service - Call Offer (SS-CO) (listed below). DEFINITY ECS 
uses only the first way.
•Network invocation (immediate) — the PTN automatically invokes SS-CO 
whenever the calling user makes a call to a user that is busy, if required by the 
service profile of the calling user. 
•Consultation — the calling user, on being informed that a call has failed because it 
is busy at the destination and that SS-CO may be possible, is able, within a defined 
time period (consultation timer), to request invocation of SS-CO. 
•Immediate invocation — the calling user is able to request invocation of SS-CO as 
part of the initial call set-up.
•Network invocation (delayed) — the network, having informed the calling user 
that a call has failed because it is busy at the destination, invokes SS-CO 
automatically unless the calling user initiates call clearing within a defined time 
period (automatic call offer invocation timer).
DEFINITY ECS The effect of QSIG SS-CO on the terminating end is similar to the 
DCS Call Waiting feature with the exception that for Call Waiting, the calling side 
(user or PBX) does not have to convey any special message to invoke the feature. The 
Call Waiting Termination feature is driven based on the terminating user (for 
instance, single line analog set user with Call Waiting enabled).
For QSIG Call Offer, DEFINITY takes advantage of the additional information 
available from the far end, if QSIG Call Offer invokes successfully, and provides 
similar information to the calling user as the Call Waiting feature provides for on 
internal calls, with the exception that the display update will be “offered” instead of 
“wait” to reflect invocation of QSIG Call Offer service.
On successful invocation of the QSIG Call Offer service, DEFINITY provides the 
following:
•To the busy analog set user, the same tone as Call Waiting Termination feature, or
•To the busy Multi call-appearance set (for instance, at least one call-appearance is 
busy for an active call and at least one call-appearance is available for incoming 
calls) user, the available appearance rings normally.
For incoming QSIG calls, the QSIG Call Offer service may use path retention which 
is a generic mechanism to retain the signaling connection so that the originating party 
can decide whether to invoke the supplementary service. The network connection can 
be retained for more than one of the supplementary services for which path retention 
has been invoked.
Call CompletionUse this feature to provide QSIG Supplementary Service - Call Completion (SS-CC).
The Supplementary Service - Completion of Calls to Busy Subscribers (SS-CCBS) 
and Supplementary Service - Completion of Calls on No Reply (SS-CCNR) are the 
equivalent QSIG features of Automatic Callback On Busy and Automatic Callback 
on No Answer, respectively. 
						

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An analog voice terminal user activates SS-CCBS or SS-CCNR by pressing the Recall 
button or flashing the switchhook and then dialing the Automatic Callback (ACB) 
Activation feature access code. An analog user can activate only one ACB call at any 
given time.
A multiappearance voice terminal user can activate SS-CCBS or SS-CCNR for the 
number of ACB buttons assigned to the terminal. 
SS-CC Options
QSIG SS-CC has the following major options that are negotiated between the 
Originating and the Terminating PBX:
1  Path reservation — there are two methods of establishing the CC call:
 a  path reservation method
 b  non-reservation method
2  Retention of signaling connection — there are two ways in which SS-CC uses 
call independent signaling connections:
 a  connection retention method
 b  connection release method
3  Service retention — there are two possible behaviors when User B is found to be 
busy again after User A responds to SS-CC Recall:
 a  service retention method
 b  service cancellation method
As an originating PBX for QSIG SS-CC, DEFINITY ECS will select the following 
major options:
•non-reservation method for the Path Retention option
•connection release method for the Retention of Signaling connection option
•service cancellation method for the Service Retention option
As a Terminating PBX for QSIG SS-CC, DEFINITY ECS will select the following 
major options:
•non-reservation method for the Path Retention option
•either the connection release method or the connection retention method for the 
Retention of Signaling connection option depending on which the originating 
PBX requests. 
•service cancellation method for the Service Retention option
QSIG Centralized  
AUDIXQSIG allows users on a remote node to “cover” to an AUDIX on another node. The 
original calling and called party information is provided to AUDIX so that each is 
identified properly during message recording/retrieval.
To use centralized AUDIX, you must use QSIG Diversion. On a remote switch, the 
call covers using Diversion to the hunt group assigned to AUDIX on the host switch. 
Then the host switch sends all the appropriate information to AUDIX so that AUDIX 
correctly answers the call.  
						

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Other QSIG Centralized Messaging
With a QSIG centralized messaging system, the remote switch is called a served user 
switch. When an AUDIX system supports a QSIG network, the served user switch 
does not need to be a DEFINITY ECS, but the host, or message center, switch must 
be. 
QSIG allows a DEFINITY switch to be a served user switch of a non-DEFINITY 
message center switch. Therefore, the messaging system connected to the message 
center switch can serve the DEFINITY switch if that messaging system has a QSIG 
interface. Octel Serenade is such a messaging system.
The users on a served user switch in a QSIG messaging network may use only one 
message center. However, the message center switch may served multiple served user 
switches, via DCS as well as QSIG. 
What you get with QSIG Centralized  AUDIX
•
Calls to users on a remote PBX cover or forward correctly and are answered by 
AUDIX.
~With a personalized greeting
~With appropriate busy or not available greeting, depending upon the reason the 
call was redirected
~Caller can leave a message for the called party
•Once a subscriber logs into AUDIX (by dialing the AUDIX number and entering 
the extension and password), the subscriber can perform the following activities:
~Listen to or delete messages (voice, fax, or text)
~Leave a message for other subscribers on the same AUDIX without calling 
them
~Forward a message to another subscriber on the same AUDIX
~Access the AUDIX directory to address a message (*A)
~Access the AUDIX directory to find a subscriber’s extension (**N)
~Record or change your greeting
~Transfer out of AUDIX (*T or 0)
•Message Waiting Indication (typically a lamp, but may be a stutter dial tone or 
display) indicates the presence of new messages. 
I 
If another vendor’s switch, acting as a served user switch, does not provide this 
functionality, the call will not cover properly to a DEFINITY ECS message center 
switch complex.
•When a remote subscriber logs in to AUDIX from the subscriber’s phone, the 
subscriber does not need to enter his or her extension. Instead of entering the 
extension, *, the password, and *, the subscriber can enter *, the password, and 
then #.
What you do not get 
•
Leave Word Calling does not work between served user switches, though users on 
the same switch can use it.
•Transfer into AUDIX does not work from a served user switch. 
						

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Path RetentionPath Retention is a generic mechanism for retaining a network connection that can be 
used by supplementary services during call establishment.
The Originating PBX invokes path retention for one supplementary service or for 
several simultaneous supplementary services. Invoking a particular supplementary 
service means retaining the network connection if the Terminating PBX encounters 
the appropriate conditions. The Originating PBX is informed of the reason for 
retaining the connection. It then decides (for example, by consulting the calling user) 
whether to invoke the supplementary service. Under some circumstances in which the 
network connection is retained, more than one of the supplementary services for 
which path retention has been invoked may be applicable.
Successive retentions of the network connection by the Terminating PBX following a 
single path-retention invocation by the Originating PBX are possible. This is a result 
of different conditions being encountered at the Terminating PBX. When an attempt 
is made to invoke a supplementary service for which the network connection has been 
retained, a further condition can be encountered that can cause the network 
connection to be retained again for the same or a different supplementary service.
Path retention is specified in terms of a Path Retention entity existing within the 
Coordination Function at the Originating PBX and at the Terminating PBX.
QSIG Centralized Attendant Services
QSIG Centralized 
Attendant Service 
(QSIG-CAS)DEFINITY ECS supports two versions of CAS: RLT-CAS and QSIG-CAS.
The CAS feature enables one or more Branch PBXs to concentrate their attendants on 
one Main PBX.  CAS provides transparency between PBXs of most features that are 
normally available to the basic attendant service. 
RLT-CAS uses an analog RLT network to optimized trunk utilization. QSIG-CAS 
does not use RLT. By using QSIG Transfer and QSIG Path Replacement or QSIG 
Diversion with Rerouting,  the same optimization as using RLT can be accomplished 
with QSIG-CAS. Using QSIG CAS, you eliminate the need to have a separate analog 
RLT network.
All current QSIG features and RLT-CAS features are available with QSIG-CAS.
Potential Drawbacks
There are a few potential drawbacks when using QSIG-CAS:
1  Unlike RLT, QSIG Path Replacement does not work immediately.  This means 
that resources are being utilized longer during QSIG-CAS as opposed to 
R LT- C A S .  
2  Unlike RLT, QSIG Path Replacement is not guaranteed. 
3  Like RLT, QSIG Path Replacement does not enable a branch PBX to act as a 
gateway PBX.
4  No path replacement functionality takes place during or after a conference.  
						

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QSIG CAS functions in RLT-CAS
The following QSIG-CAS functions are currently in RLT-CAS:
•Attendant-seeking calls at a branch reach the attendant at the main
•Attendant splitting away and calling the extended to party
•Night Service
•Monitoring agents, per attendant group
QSIG CAS functions not in RLT CAS
The following QSIG-CAS functions are currently not in RLT-CAS:
•Announcements for attendant seeking calls
•Attendant calls enter the attendant queue, with priorities (calls that originate from 
the branch do not have different priorities in the queue) 
•Attendant display of user’s COR
•Attendant split/swap
•QSIG Path Replacement kicking in after the transfer
•Attendant Return Call (Release Loop Operation, returns to same attendant if 
available.  If not, then attendant group) 
•Display Enhancements
•Attendant Conference
QSIG Supplementary Services with Rerouting
QSIG Path 
Replacement DEFINITY ECS provides QSIG Additional Network Feature Path Replacement 
(ANF-PR) as defined in ISO/IEC 13863 and 13874. With this feature, a call’s 
connections between switches in a private network can be replaced with new 
connections while the call is active. 
ANF-PR is invoked when a call is transferred and improvements may be made in the 
routes. For example, after a call is transferred, the two parties on the transferred call 
can be connected directly and the unnecessary trunks are dropped off the call. The 
routing administered at the endpoints allows for a more efficient route connection.
ANF-PR selects the best route based on the preference assigned to routes in the Route 
Pattern form. Least cost Supplementary Service B (SSB) routes must be first, 
followed by more expensive routes.
Note:When routes to SSB trunks are included with routes to non-SSB 
trunks, SSB trunks must appear first on the Route Pattern form. 
This is because as soon as ANF-PR encounters a non-SSB trunk in 
the route pattern, it stops looking.
Class of Restriction (COR) and Facility Restriction Levels (FRL) are adhered to in 
routing calls. ANF-PR is not invoked on data calls because there is a period of time 
when information can be lost. 
						

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QSIG Call Forwarding 
(Diversion with 
Rerouting) This feature allows a forwarded call can be rerouted in a private network to find a 
more cost-effective or resource-efficient path.
QSIG Transfer into Lucent QSIG Voice Mail
Transfer into QSIG 
Voice MailThis feature uses QSIG Call Transfer, along with a manufacturer-specific information 
(MSI) message, to transfer a call directly into a subscriber’s mailbox when the voice 
mail system is connected to the Message Center PBX via a QSIG link.
The voice mail system must be a Lucent system that supports the QSIG Transfer Into 
QSIG Voice Mail MSI operation. 
Note:This feature currently works only with the Serenade voice mail 
system. This feature does not work with QSIG Centralized AUDIX.
The entire route from the PBX activating Transfer Into Voice Mail to the voice mail 
system must be QSIG.
QSIG Value-Added Lucent (VALU)
Value-Added Lucent (VALU) adds three forms of feature transparency to QSIG 
networks.
•Called/Busy Number — The system sends and displays across the network the 
called party’s number to the calling party during alerting. It updates the display to 
“connected number” when the called party answers the call. It also sends and 
displays a busy party’s number. This serves to confirm to the caller that he or she 
dialed the correct number.
The Called/Busy Number feature is an extension to QSIG Called/Busy Name. For 
additional information, see QSIG Name and Number Identification  (page 361).
The Called/Busy Number never displays alone; it displays only if the Called/Busy 
Name is available (for instance, received from the far end and marked 
“presentation allowed”). In contrast, upon receipt of a Calling Number without a 
Calling Name, the number displays with the words “CALL FROM.”
•Distinctive Ringing — QSIG VALU provides two kinds of distinctive ringing 
across the network: internal and external.
•Call Coverage — The system allows calls to be covered by extensions across the 
network. This coverage operates similarly to DCS Call Coverage  (page 315), 
though the connectivity of the network itself differs. If administered, path 
replacement is invoked after coverage.
These features work with phone users as well as for a centralized attendant service. 
						

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QSIG Protocols
QSIG signaling protocols are based on ITU-T (formerly CCITT) Q.931 access 
protocols across the Q reference point. QSIG standards are also supported by the 
ISDN Private Networking Specification (IPNS) Forum. DEFINITY ECS QSIG 
complies with a number of international regulations. For example, QSIG:
•Complies with ISO standard 11572 for layer 3 to support private-network 
connectivity. 
•Meets requirements for the ISO Private Network Generic Functional Procedures 
(ISO standard 11582) for call-related supplementary services. 
•Supports call-related supplementary service transport, Abstract Syntax Notation 1 
(ASN.1)/Basic Encoding Rules (BER), and Remote Operation Service Element 
(ROSE) services/protocols.
•Provides the Name and Number Identification supplementary service as defined 
by ISO Standards 13864, 13868, and 11572. 
•Provides Call Forwarding (Diversion) as defined by ISO Standards 13872 and 
13873.
•Provides Call Transfer as defined by ISO Standards 13865 and 13869.
Temporary Signaling Connection (TSCs)
A Temporary Signaling Connection (TSC) provides a temporary signaling path 
through ISDN switches for exchanging supplementary service information (for 
example, exchange Facility Information Elements in call control messages, 
FACILITY messages, or a combination of both on ISDN D-channels. There is no 
B-channel related to the connection; no data or voice transmissions take place. 
There are two types of temporary signaling connections:
•Call Associated (CA-TSC)
•Non-Call Associated (NCA-TSC)
CA-TSC (DCS only)A CA-TSC refers to a service for exchanging USER INFORMATION messages 
associated with an ISDN B-channel connection by the call reference value of the call 
control data packets. On DEFINITY ECS, this type of TSC is used only for DCS 
features on ISDN-PRI Signaling Groups administered with Supplementary Service 
Protocol a. 
						

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NCA-TSCAn NCA-TSC is a connection not related with any ISDN B-channel connections. 
DECINITY ECS supports two types of NCA-TSC that conform to two different 
protocol standards:
•The non-QSIG AT&T type of NCA-TSC is used for the DCS over ISDN-PRI 
D-channel and DCS AUDIX applications. Only ISDN-PRI Signaling Groups 
administered with Supplementary Service Protocol a support AT&T NCA-TSCs. 
For further information, see page 322.
•The QSIG type of NCA-TSC is used for certain QSIG features such as Call 
Completion (Automatic Call Back). This type of NCA-TSC is referred to in the 
QSIG protocol standards as a Call-Independent Signaling Connection (CISC). 
Only ISDN-PRI Signaling Groups administered with Supplementary Service 
Protocol b support QSIG NCA-TSCs. In addition, BRI trunk D-channels support 
QSIG NCA-TSCs.
An NCS-TSC for QSIG is not administered ahead of time, but is invoked 
dynamically by the QSIG feature that needs it. Some QSIG features remove the 
NCA-TSC when it is no longer needed; others leave the it active for a longer 
period of time.
DEFINITY ECS does not provide gateway functionality between a QSIG 
NCA-TSC and an AT&T NCA-TSC. For example, although a call can be routed 
from a DCS network into a QSIG network, it is not possible for the caller in this 
case to invoke an automatic callback.