Nortel Modular Ics 6.1 Installer Guide

							Welcome to ISDN / 51
P0603534  02Modular ICS 6.1 Installer Guide
MCDN trunk features
Systems with MCDN Private Networking connections can 
provide these trunk routing features:
• Trunk Route Optimization (TRO) finds the most direct 
route through the network to send a call between nodes. 
This function occurs during the initial alerting phase of a 
call.
• ISDN Call Connection Limitation: The ICCL feature 
piggybacks on the call initiation request and acts as a check 
at transit PBX points to prevent misconfigured routes or 
calls with errors from blocking channels.
• Trunk Anti-tromboning (TAT) is a call-reroute feature that 
works to find better routes during a transfer of an active 
call. This feature acts to prevent unnecessary tromboning 
of trunks. This action occurs after the speech path has been 
established.
Call by Call service selection for PRI
Call by Call service selection allows a user to access services 
or private facilities over a PRI line without the use of dedicated 
facilities. Various types of services such as FX, Tie, and 
OUTWATS are available, depending on the Protocol that is 
selected. Private network settings are used for tandem 
networking and Advanced Private Networking.
Outgoing calls are routed through a dedicated PRI Pool and the 
calls can be routed based on various schedules. 
For information about system programming of this feature, see 
Programming Call by Call service selection on page 460.  
						

							52 / Welcome to ISDN
Modular ICS 6.1 Installer GuideP0603534  02
For services information about dialing plans and PRI, see 
Networking with Norstar on page 99 and Dialing Plan on page 
436.
Refer to the hardware section for Call-by-call routing on page 
485. 
Emergency 911 dialing
Modular ICS 6.1 with the ISDN PRI feature is capable of 
transmitting the telephone number and internal extension 
number of a calling station dialing 911 to the Public Switched 
Telephone Network. 
State and local requirements for support of Emergency 911 
dialing service by Customer Premises Equipment vary. 
Consult your local telecommunications service provider 
regarding compliance with applicable laws and regulations. 
For most installations, the following configuration rules 
should be followed, unless local regulations require other 
settings.
• All PSTN connections must be over PRI.
• In order for all sets to be reachable from the Public Safety 
Answering Point (PSAP), the system must be configured 
for DID access to all sets. In order to reduce confusion, the 
dial digits for each telephone should be configured to 
correspond to the extension number (DN).
• The OLI digits for each telephone should be identical to 
the DID dialed digits for the telephone.
• The System Coordinator is responsible for maintaining a 
site map or location directory that allows emergency 
personnel to rapidly locate a telephone given its DID 
number. This list should be kept up to date and readily 
available, and can be included in the Programming Record 
						

							Welcome to ISDN / 53
P0603534  02Modular ICS 6.1 Installer Guide
• The routing table should route 911 to a public line or line 
pool.
• If attendant notification is required, the routing table must 
be set up for all 911 calls to use a dedicated line which has 
an appearance on the attendant console.
Note:  The actual digit string 911 is not hard-coded into the 
system. More than one emergency number can be 
supported 
MCID (Profile 2)
The MCID feature allows you to use ≤°·‡ to have 
call information recorded on the central office database for an 
incoming call on a specific line (EUROISDN lines, only).
The user must invoke the feature code during the active call or 
within 30 seconds (time varies on different networks) after the 
caller hangs up. The user must remain on the line to enter the 
code.
Network Call Diversion (Profile 2)
This feature is a network function of ETSI E1 lines that allows 
forwarding and redirection of calls outside the Norstar 
network when using an ETSI ISDN line. Functionality is 
similar to that of External Call Forward (ECF). NCD redirects 
calls using the same line on which they arrive. Call forward is 
efficient since there is no need for additional outside lines.
DTI card configured as a PRI card
The DTI card on your Norstar system can be configured to 
support PRI. For information about configuring a DTI card as 
a PRI type card, see Provisioning the DTI card for PRI on page 
483. 
						

							54 / Welcome to ISDN
Modular ICS 6.1 Installer GuideP0603534  02
ISDN hardware
To support connections to an ISDN network and ISDN 
terminal equipment, your Modular ICS must be equipped with 
one or more BRI cards (BRI-U or BRI-ST), a DTI card 
configured for PRI, and a Combination Fiber 6-port Services 
Cartridge or a Services Cartridge.
DTI card configured as PRI
A DTI card configured as PRI provides one T loop. Refer to 
T reference points on page 58 for more information.
In most PRI network configurations, you need one DTI card 
configured as PRI in your ICS to act as the primary clock 
reference. The only time when you may not have PRI 
designated as the primary clock reference is in a network 
where your Norstar system is connected back-to-back with 
another switch using a PRI link, such as is the case with the 
Advanced Private Networking configuration.
However, if the other switch is loop-timed to your Norstar 
system, your DTI card, configured as PRI, can be designated 
as a timing master. 
If your Norstar has two DTI cards configured as PRI, you 
cannot assign both cards as the primary reference or both cards 
as the secondary reference. You can only have one primary 
reference and one secondary reference per system. Refer to 
ClockSrc on page 492 for more information.
BRI Card
The loops on BRI-U and BRI-ST cards can be programmed to 
support either network or terminal connections. This allows 
you to customize your arrangement of lines, voice terminals, 
data terminals and other ISDN equipment.  
						

							Welcome to ISDN / 55
P0603534  02Modular ICS 6.1 Installer Guide
Detailed wiring information for BRI and PRI network and 
terminal connections is included in the Installation on page 
219.
BRI-U2 and BRI-U4 card
A BRI-U2 card supports two loops and the BRI-U4 supports 
four loops. Each loop can be individually programmed to 
provide one of the following:
• a U-LT reference point connection for terminal equipment 
(TE) with built-in NT1 functionality (U interface)
• a U-NT reference point connection for direct connection to 
an ISDN network
BRI-ST card
A BRI-ST card provides four loops. Each loop can be 
individually programmed to one of the following:
• an S reference point connection (S loop) to ISDN terminal 
equipment (TE)
• a T or S reference point connection (T loop or S loop) to an 
ISDN network using an external NT1
U-LT reference point
The U-LT reference point connection provides a point-to-
point digital connection between Norstar and TE equipped 
with a U interface.
A U-LT loop supports up to eight ISDN DNs, which identify 
TE to the ICS. Refer to the example below. 
						

							56 / Welcome to ISDN
Modular ICS 6.1 Installer GuideP0603534  02
U-NT reference points
The U-NT reference point connection provides a point-to-
point digital connection between the ISDN network and the 
ICS.
A U-NT loop provides lines that can be used by all Norstar 
telephones, peripherals and applications, and ISDN TE.
U-NT and U-LT loops can be used in combination to provide 
D-packet service for a point-of-sale terminal adapter (POSTA) 
or other D-packet device. D-packet service is a 16 kbps data 
transmission service that uses the D-channel of an ISDN line.
To deliver D-packet service, a network connection (U-NT) is 
programmed to work with a terminal connection (U-LT). The 
loops must be on the same physical card. For example, if the 
network connection is a loop found on the BRI Card in Slot 1, 
the terminal connection must be a loop found on the same card.
point-to-point
U-LT
ICS
U interface TE
network
 connection
U-NT
ICS
ISDN 
						

							Welcome to ISDN / 57
P0603534  02Modular ICS 6.1 Installer Guide
S reference point
The S reference point connection provides either a point-to-
point or point-to-multipoint digital connection between 
Norstar and ISDN terminal equipment (TE) that uses an 
S interface.
S loops support up to seven ISDN DNs, which identify TE to 
the ICS.
In
s
p
e
c
t F
O
R
W
A
R
D
 C
a
lle
rsInspect FORWARD CallersM
X
PMXP
S
S
In
s
p
e
c
t F
O
R
W
A
R
D
 C
a
lle
rsInspect FORWARD CallersM
X
PMXP
In
s
p
e
c
t 
F
O
R
W
A
R
D
 C
a
ll
e
rsInspect FORWARD CallersM
X
PMXP
point-to-point
ISDN TE
ISDN TE
ISDN TE
(with terminating 
resistors)ICS
ISDN TE
(with terminating resistors) 
						

							58 / Welcome to ISDN
Modular ICS 6.1 Installer GuideP0603534  02
T reference points
The T reference point connections provide a point-to-point 
digital connection between the ISDN network and Norstar.
A T loop provides lines that can be shared by all Norstar 
telephones, peripherals and applications, and ISDN TE.
A T loop can be used in combination with an S loop to provide 
D-packet service for a point-of-sale terminal adapter (POSTA) 
or other D-packet device. D-packet service is a 16 kbps data 
transmission service that uses the D-channel of an ISDN line.
To deliver D-packet service, a network connection (T loop) is 
programmed to work with a terminal connection (S loop). The 
loops must be on the same physical card. For example, if the 
network connection is a loop found on the BRI Card in Slot 1, 
the terminal connection must be a loop found on the same card
network
 connection
T
ICS
ISDN 
						

							Welcome to ISDN / 59
P0603534  02Modular ICS 6.1 Installer Guide
Clock source for ISDN cards
Systems with ISDN interfaces need to synchronize clocking 
with the ISDN network and any connected ISDN terminal 
equipment. Clocking synchronization is supported by either a 
Combination Fiber 6-port Services Cartridge or a Services 
Cartridge. 
The Modular ICS derives timing from the network using 
U-NT and T reference points (loops). Terminal equipment on 
U-LT and S reference points (loops) derive timing from the 
ICS.
Systems synchronize clocking to the first-available functional 
network connection. If there are excessive errors on the 
reference network connection, or if the loop fails, the next-
available functional network connection is used for clock 
synchronization. 
The clock synchronization process generates alarm codes and 
event messages. See the Alarm codes on page 533 and Event 
messages on page 541 for more information.
When you configure the network connections to the Modular 
ICS, you should take into account the system preferences for 
selecting loops for synchronization:
• lower numbered loops have preference over higher 
numbered loops
• the loop preference order is: 201, 202, 203, 204, 225, 226, 
227, 228 (Profile 1, 3 and 4), or 201, 202, 203, 204, 231, 
232, 233, 234 (Profile 2)
• the system skips U-LT, S, and analog loops when selecting 
a network connection for synchronization 
						

							60 / Welcome to ISDN
Modular ICS 6.1 Installer GuideP0603534  02
Systems with only U-LT and S loops act as timing masters for 
the attached terminal equipment (TE), and are not 
synchronized to the network. ISDN TE without access to a 
network connection (BRI lines) has limited or no 
functionality.
If your system has both a BRI and a DTI card configured as 
PRI installed, it is recommended that you use PRI as the 
primary clock source, see DTI card configured as a PRI card 
on page 53.
Other ISDN BRI equipment: NT1
The NT1 (network termination type 1) connects an S interface 
(four-wire) to a U interface (two-wire). In most cases, it 
connects loops from a BRI-ST card to the network connection, 
which uses the U interface. It can also connect S interface 
terminal equipment (TE) to the U loop from a BRI-U2 or 
BRI-U4 Card.
An NT1 is not required to connect from the network to BRI-U 
cards or to connect U interface TE to an ICS equipped with 
BRI-U cards.
The NT1 converts and reformats data so it can be transmitted 
to and from the S or T connection. In addition, it manages the 
maintenance messages travelling between the network and the 
NT1, and between the NT1 and the ICS.
The NT1 from Nortel Networks is packaged two ways:
• as a stand alone package, which contains one NT1 card 
(NTBX80XX) and a power supply (NTBX81XX)
• as a modular package, which contains up to 12 NT1 cards 
(NTBX83XX) and a power supply (NTBX86AA)