Lucent Technologies DEFINITY Enterprise Communications Server Release 8.2 Instructions Manual

							DEFINITY ECS Release 8.2
Administrator’s Guide  555-233-506  Issue 1.1
June 2000
Features and technical reference 
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Given this facility list concept, the algorithms have the ability to search for trunks, 
by facility, in an attempt to satisfy the bandwidth requirements of a given 
wideband call. If one facility does not have enough available bandwidth to 
support a given call, or it is not used for a given call due to the constraints 
presented in the following section, then the algorithm searches the next facility in 
the trunk group for the required bandwidth (if there is more than one facility in the 
trunk group).
In addition to searching for channels based on facilities and required bandwidth, 
Port Network (PN) preferential trunk routing is also employed. This PN routing 
applies within each algorithm at a higher priority than the constraints put on the 
algorithm by the parameters listed later in this section. In short, all facilities that 
reside on the same PN as the originating endpoint are searched in an attempt to 
satisfy the bandwidth of a given call, prior to searching any facilities on another 
PN.
Direction of trunk/hunting within facilities
The algorithms have the ability to select trunks from low B-channel to high 
B-channel or from high B-channel to low B-channel with an ISDN facility. This is 
a per ISDN trunk group option, but infers the direction of search within all ISDN 
facilities (or portions of those facilities) administered within that trunk group. 
This is necessary so the selection of trunks are not prone to as much glare as they 
otherwise would be if trunks were chosen in the same direction by both user and 
network sides of the ISDN interface. Note that in previous DEFINITY ECS 
releases, the order in which trunks were selected, whether through linear or 
circular hunting, would always be with respect to the order in which trunks were 
administered within the trunk group. Now, with the support of wideband services, 
all trunks within an ISDN trunk group optioned for wideband are ordered based 
on this new “direction of trunk/hunt with facilities” parameter, and without regard 
to the order in which trunks are administered within the trunk group. If an ISDN 
trunk group is not optioned for wideband, then a cyclical trunk hunt based on the 
administration of trunks within the trunk group is still available.
H11
When a trunk group is administered to support H11, the algorithm to satisfy a call 
requiring 1,536 Kbps of bandwidth uses a fixed allocation scheme. That is, the 
algorithm searches for an available facility using the following facility-specific 
channel definitions.
nT1: H11 can only be carried on a facility without a D-channel being 
signaled in an NFAS arrangement (B-channels 1-24 are used).
nE1: Although the 1,536-kbps bandwidth could be satisfied using a number 
of fixed starting points (for example, 1, 2, 3, etc.) the only fixed starting 
point being supported is 1. Hence, B-channels 1–15 and 17–25 are always 
used to carry an H11 call on an E1 facility. 
						

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If the algorithm cannot find an available facility within the trunk group that meets 
these constraints, then the call is blocked from using this trunk group. In this case, 
the call may be routed to a different trunk group preference via Generalized Route 
Selection (GRS), at which time, based on the wideband options administered on 
that trunk group, the call would be subject to another hunt algorithm (that is, either 
the same H11 algorithm or perhaps an N x DS0 algorithm described in a later 
paragraph).
This same hunt algorithm, when offered any other call (other than a 1,920-kbps 
call) attempts to preserve idle facilities by selecting trunk(s) in a partially 
contaminated facility if one exists. If the bandwidth required by this call cannot be 
satisfied by any partially contaminated facility, then the call is placed on available 
trunk(s) within an idle facility, thus contaminating the facility. Again, facilities are 
selected via the trunk group’s facility list and with PN preference, and trunk(s) 
within a facility are selected based on the direction of channel search 
administered. Note that on a T1 facility, a D-channel is not considered a busy 
trunk and results in a facility with a D-channel always being partially 
contaminated. On an E1 facility, however, a D-channel is not considered a busy 
trunk because H11 and H12 calls may still be placed on that facility; an E1 facility 
with a D-channel and idle B-channels is considered an idle facility.
H12
Since H12 is 1,920 Kbps which is comprised of 30 B-channels, a 1,920-kbps call 
can only be carried on an E1 facility. As with H11, the hunt algorithm uses a fixed 
allocation scheme with channel 1 being the fixed starting point. Hence, an H12 
call always is carried on B-channels 1 to 15 and 17 to 31 on an E1 facility (as 
illustrated in the following table). When offered any other call (other than a 
1,536-kbps call), the algorithm behaves as it does when H11 is optioned.
DS0s Comprising Each Channel
FacilityISDN
Interface H11 H12
T1
T123B + D
24B (NFAS)-
1-24-
-
E1
E130B + D
31B (NFAS)1-15, 17-25
1-15, 17-251-15, 17-31
1-15, 17-31 
						

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H0
When a trunk group is administered to support H0, the algorithm to satisfy a call 
requiring 384 Kbps of bandwidth also uses a fixed allocation scheme. Unlike the 
H11 fixed scheme which only supports a single fixed starting point, the H0 fixed 
scheme supports four (T1) or five (E1) fixed starting points. The H0 algorithm 
searches for an available quadrant within a facility based on the direction of trunk 
or hunt administered. If the algorithm cannot find an available quadrant within 
any facility allocated to this trunk group, then the call is blocked from using this 
trunk group. Again, based on GRS administration, the call may route to a different 
trunk group preference and be subject to another algorithm based on the wideband 
options administered.
This same trunk or hunt algorithm, when offered any narrowband or N x DS0 call, 
attempts to preserve idle quadrants by choosing a trunk(s) in a partially 
contaminated quadrant if one exists. If a partially contaminated quadrant capable 
of carrying the call does not exist, then the call is placed on available trunk(s) 
within an idle quadrant, thus contaminating the quadrant. Again, facilities are 
selected via the trunk group’s facility list and with PN preference, and a trunk(s) 
within a facility is selected based on the direction administered. Note that a 
D-channel is considered a busy trunk and results in the top most quadrant of a T1, 
B-channels 19 to 24, always being partially contaminated. This is not true for 
NFAS.
If this H0 optioned trunk group is also administered to support H11, H12, or N x 
DS0, then this algorithm also attempts to preserve idle facilities. In other words, 
when offered a narrowband, H0, or N x DS0 call, the algorithm searches 
partially-contaminated facilities before it searches to idle facilities.
N x DS0
For the N x DS0 multi-rate service, a trunk group parameter determines whether a 
floating or a flexible trunk allocation scheme is to be used. The algorithm to 
satisfy an N x DS0 call is either floating or flexible.
nFloating (Contiguous) — In the floating scheme, an N x DS0 call is placed 
on a contiguous group of B-channels large enough to satisfy the requested 
bandwidth without any constraint being put on the starting channel (that is, 
no fixed starting point trunk).
nFlexible — In the flexible scheme, an N x DS0 call is placed on any set of 
B-channels as long as the requested bandwidth is satisfied. There is 
absolutely no constraint such as contiguity of B-channels or fixed starting 
points. Of course, as with all wideband calls, all the B-channels comprising 
the wideband call must reside on the same ISDN facility. 
						

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Regardless of the allocation scheme employed, the N x DS0 algorithm, like 
the H11 and H12 algorithms, attempts to preserve idle facilities when 
offered B, H0, and N x DS0 calls. This is important so that N x DS0 calls, 
for large values of N, have a better chance of being satisfied by a given 
trunk group. However, if one of these calls cannot be satisfied by a 
partially-contaminated facility and an idle facility exists, a trunk on that 
idle facility is selected, thus contaminating that facility.
There are additional factors to note regarding specific values of N and the 
NxDS0 service:
— N = 1 — this is considered a narrowband call and is treated as any 
other voice or narrowband-data (B-channel) call.
— N = 6 — if a trunk group is optioned for both H0 and N x DS0 
service, a 384-kbps call offered to that trunk group is treated as an 
H0 call and the H0 constraints apply. If the H0 constraints cannot be 
met, then the call is blocked.
— N = 24 — if a trunk group is optioned for both H11 and N x DS0 
service, a 384-kbps call offered to that trunk group is treated as an 
H0 call and the H0 constraints apply. If the H0 constraints cannot be 
met, then the call is blocked.
— N = 24 — if a trunk group is optioned for both H11 and N x DS0 
service, a 1,536-kbps call offered to that trunk group is treated as an 
H11 call and the H11 trunk allocation constraints apply.
— N = 30 — if a trunk group is optioned for both H12 and N x DS0 
service, a 1,920-kbps call offered to that trunk group is treated as an 
H12 call and the H12 trunk allocation constraints apply.
Glare prevention
Glare occurs when both sides of an ISDN interface select the same B-channel for 
call initiation. For example, a user side of an interface selects the B-channel for an 
outgoing call and, before the switch receives and processes the SETUP message, 
the switch selects the same B-channel for call origination. Since wideband calls 
use more channels, the chances of glare are greater. Glare conditions can be 
limited with proper channel administration, but they may never be eliminated and 
some calls may still be dropped.
Some glare situations might not be resolvable. In one case, the network and the 
user side may send SETUP messages simultaneously or nearly simultaneously. 
Another glare scenario can occur in the brief window after the SETUP message 
has been sent but before the first response is received from the switch at the other 
side of the interface. If an incoming SETUP arrive during this window, the 
incoming SETUP message is allowed to proceed and the outgoing call is dropped. 
Various glare situations and their resolution are described in the following table. 
						

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DEFINITY ECS does not negotiate channels for wideband calls.
GLARE RESOLUTION
Outgoing 
Call TypeIncoming 
Call TypeSwitch-Supporting
User ProtocolSwitch-Supporting 
Network Protocol
B-channel B-channel No negotiation
Incoming call (from 
network) winsNegotiation is attempted
Incoming call (from user) 
dropped if negotiation is 
unsuccessful
Outgoing call (to network) 
retried on another trunkOutgoing call (to user) stays 
up
B-channel(s) Wide No negotiation No negotiation
Incoming call (from 
network) droppedIncoming call (from user) 
dropped
Outgoing calls (to network) 
stay up but likely are 
dropped by network 
because channels are in use, 
although there is a 
possibility some switches 
might negotiate these calls.Outgoing calls (to user) stay 
up and possibly stay up if 
other side lets the network 
call win.
Wide B-channel(s) No negotiation Negotiation is attempted
Incoming call (from 
network) winsIncoming call (from user) 
dropped if negotiation is 
unsuccessful
Outgoing call (to network) 
retried on another trunkOutgoing call (to user) stays 
up
Wide Wide No negotiation No negotiation
Incoming call (from 
network) droppedIncoming call (from user) 
dropped
Outgoing call (to network) 
stays up but likely are 
dropped by network 
because channels are in use.Outgoing call (to user) stays 
up and may not be dropped 
by other side because other 
side, if it is not a DEFINITY 
ECS, may let the network 
call win.
Continued on next page 
						

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To reduce glare probability, the network needs to be administered so both sides of 
the interface select channels from opposite ends of facilities. For example, on a 
23B+D trunk group, the user side could be administered to select B-channels 
starting at channel 23 while the network side would be administered to start 
selecting at channel 1. Using the same example, if channel 22 is active but channel 
23 is idle, the user side should select channel 23 for re-use. This is known as linear 
trunk hunt and is the hunt option used by DEFINITY ECS for wideband.
Blocking prevention
Blocking occurs when insufficient B-channels required to make a call are 
available. Narrowband calls require only one channel so blocking is less likely 
than with wideband calls that require multiple B-channels. Blocking also occurs 
for wideband calls when bandwidth is not available in the appropriate format (that 
is, fixed, floating, or flexible).
To reduce blocking, the switch selects trunks for both wideband and narrowband 
calls to maximize availability of idle fixed channels for H0, H11, and H12 calls 
and idle floating channels for N x DS0 calls that require a contiguous bandwidth. 
The strategy for preserving idle channels depends on the channel type. The 
chances for blocking are reduced if you use a flexible algorithm, assuming it is 
supported on the other end.
Considerations
nFor example, if the user side is provisioned to start at the high side (DS0 
23) and DS0 22 is idle but DS0 23 is active, reselect DS0 22 for the next 
call. This is known as linear trunk hunting. Only the direction of hunt is 
administrable. 
Channel Type Blocking Minimization Strategy
H0 Preserve idle quadrants
H11 Preserve idle facilities
H12 Preserve idle facilities
Flexible NxDS0 Preserve idle facilities
Floating NxDS0 Preserve idle facilities as first priority 
						

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Interactions 
nAdministered Connections
Provides call initiation for WAEs. All Administered Connections that 
originate from WAEs use the entire bandwidth administered for WAE. The 
destination of an Administered Connection can be a PRI endpoint.
nAutomatic Circuit Assurance 
Treats wideband calls as single-trunk calls so that a single ACA-referral 
call is made if an ACA-referral call is required. The call is on the lowest 
B-channel associated with the wideband call.
nCall Coverage
A wideband endpoint extension cannot be administered as a coverage point 
in a call-coverage path.
nCall Detail Recording 
When CDR is active for the trunk group, all wideband calls generate CDR 
records. The feature flag indicates a data call and CDR records contain 
bandwidth and Bearer Capability Class (BCC). 
nCall Forwarding
You must block Call Forwarding through Class of Service.
nCall Management System and Basic Call Management System
Wideband calls can be carried over trunks that are measured by CMS and 
BCMS. Wideband endpoints are not measured by CMS and BCMS.
nCall Vectoring
PRI endpoints use a vector-directory number when dialing. For example, 
PRI endpoint 1001 dials VDN 500. VDN 500 points to Vector 1. Vector 1 
can point to other PRI endpoints such as route-to 1002, or route-to 1003, or 
busy.
Call Vectoring is used by certain applications. When an incoming 
wideband call hunts for an available wideband endpoint, the call can route 
to a VDN, that sends the call to the first available PRI endpoint. 
nClass of Restriction
COR identifies caller and called-party privileges for PRI endpoints. 
Administer the COR so that account codes are not required. Forced entry of 
account codes is turned off for wideband endpoints. 
nClass of Service
COS determines the class of features that a wideband endpoint can 
activate.  
						

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nFacility and Non-Facility Associated Signaling
FAS and NFAS with or without D-Channel Backup requires administration 
via signaling groups for trunk-side wideband interfaces.
nFacility Busy Indication
You can administer a busy-indicator button for a wideband-endpoint 
extension, but the button does not accurately track endpoint status.
nFacility Test Calls
Use Facility Test Calls to perform loop-back testing of the wideband call 
facility.
nGeneralized Route Selection
GRS supports wideband BCC to identify wideband calls. GRS searches a 
route pattern for a preference that has wideband BCC. Route preferences 
that support wideband BCC also support other BCCs to allow different call 
types to share the same trunk group.
nCO Trunk (TTC - Japan) Circuit Pack
The CO Trunk (TTC - Japan) circuit pack cannot perform wideband 
switching. No member of the circuit pack should be a member of a 
wideband group.
World-Class Tone Detection and 
Generation
World-Class Tone Detection allows DEFINITY ECS to identify and handle 
different types of call-progress tones. The tone detector and identification is used 
to display on Data Terminal Dialing and for deciding when to send digits on trunk 
calls through Abbreviated Dialing, ARS, AAR, and Data Terminal Dialing.
World-Class Tone Generation allows you to define call-progress tones. You can 
select values for frequency and cadence. If you do not define a call-progress tone, 
DEFINITY ECS sends silence. Brief call-waiting tones are optimal because, 
while a tone is sounding, speech cannot be heard.
A Lucent representative must administer tone detection and tone generation when 
establishing country-specific system parameters.
Interactions
nData Modules
Multiline Data Terminal Dialing is disabled if the Multiple-line Level of 
Tone Detection field is 
medium or broadband. It is enabled if the Level of 
Tone Detection field is 
precise. 
						

							References 
1615 Basic DEFINITY ECS documents 
21
DEFINITY ECS Release 8.2
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References
This chapter contains a list of user documents for the DEFINITY Enterprise 
Communications Server (ECS) Release 8.2. Most of these documents are 
backward compatible with DEFINITY ECS Release 7 systems.
To order these or other DEFINITY documents, contact the Lucent Technologies 
Publications Center at the address and phone number on the back of the title page 
of this document. A complete catalog of Business Communications Systems 
(BCS) documents is available on the World Wide Web: 
http://www.lucent.com/enterprise/documentation
Basic DEFINITY ECS documents
These documents are issued for all new and upgrade DEFINITY ECS Release 8.2 
systems.
Administration
The primary audience for these documents consists of customer administrators.
DEFINITY ECS Release 8.2 — Administrator’s Guide, 555-233-506, Issue 1
A task-based document that provides step-by-step procedures for administering 
the switch. This book contains information previously found in DEFINITY ECS 
Administration and Feature Description, 555-230-522, and DEFINITY ECS 
Release 8 — Administrator’s Guide, 555-233-502, as well as new information for 
this release. 
						

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DEFINITY ECS Release 8.2 — Administration for Network Connectivity, 
555-233-504, Issue 1
Describes how to administer connections between DEFINITY ECS switches (csi, 
si, and r models) for DCS messaging. The main focus is on TCP/IP connectivity 
introduced with DEFINITY Releases 7 and 8, including voice over IP (VOIP).
DEFINITY ECS Release 8.2 — Change Description, 555-233-411, Issue 1
Provides a high-level overview of what is new in DEFINITY ECS R8.2. 
Describes the hardware and software enhancements and lists the problem 
corrections for this release. It also includes any last-minute changes that come in 
after the remaining books have gone to production.
DEFINITY ECS Release 8.2 — System Description, 555-233-200, Issue 1
Provides hardware descriptions, system parameters, listing of hardware required 
to use features, system configurations, and environmental requirements.
DEFINITY System’s Little Instruction Book for basic administration, 
555-233-756, Issue 1
Provides step-by-step procedures for performing basic switch administration 
tasks. Includes managing phones, managing features, routing outgoing calls, and 
enhancing system security.
DEFINITY System’s Little Instruction Book for advanced administration, 
555-233-757, Issue 1
Provides step-by-step procedures for managing trunks, managing hunt groups, 
setting up night service, writing vectors, recording announcements, using reports, 
and understanding call centers.
DEFINITY System’s Little Instruction Book for basic diagnostics, 
555-233-758, Issue 1
Provides step-by-step procedures for baselining your system, solving common 
problems, reading alarms and errors, using features to troubleshoot your system, 
and contacting Lucent.