IP Server 900 Hardware Installation Manual
Ordering and installing PRI circuits
C.1
Ordering and installing PRI circuits
This section addresses things to consider when ordering and installing ISDN PRI circuits on the IP Server 900.
When ordering and provisioning such circuits, you must correctly define certain parameters in order for the PRI
to function correctly. This section is a template for a PRI order form you can use to order PRI circuits that — if
provisioned according to the order form — will be fully compatible with the IP Server 900.
PRI configuration description
•
Agent Company
— The name of the company ordering the PRI on behalf of the customer.
•
Contact
— The individual placing the PRI order.
•
Address
— Address of the agent company.
•
Customer Name
— The name of the end user’s company.
•
Circuit ID
— The circuit number (or sequence of characters and numbers) that the service provider uses to
identify the PRI circuit. This is used for identification when troubleshooting or reporting issues.
•
Support Phone Number
— The service provider’s Customer Service phone number.
•
PRI Line Protocol
— The ISDN protocol offered by the service provider. ESI strongly recommends using the
NI-2
(National ISDN-2)
protocol.
•
Framing and Line Encoding
— You
must
use
ESF
(extended super frame)
framing and
B8ZS
(binary eight-
zero substitution)
encoding.
•
Pilot/DID Numbers
— In the IP Server 900 number delivery on a PRI circuit is separated into pilot numbers
and Direct Inward Dialing (DID) numbers. It can support up to 100 pilot numbers and up to 600 DID numbers.
DID numbers are dedicated to ring to a specific phone or department and can come in on any PRI channel. Pilot
numbers ring down a specific PRI channel or group of channels, typically referred to as a hunt group. When you
create a pilot number in the IP Server 900 you must enter the maximum number of PRI “B” channels (one to 23)
that can be used for that pilot number’s hunt group. For example:
Pilot number
Name
Chs.
Day ring 1
Day ring 3
Day ring 5
Day ring 9
2145554378
ABC SYSTEMS
10
Dept. 290
2145552390
ABC SYS SVC
9
Dept. 291
2145555678
ABC SYS INTL
4
X100, X101
X100, X101 X102
Dept. 290
Important:
The total number of channels assigned across all pilot numbers should not exceed 23. Exceeding this
limit may cause system instability.
•
Glare Resolution
— Glare is a condition wherein an outgoing call and an incoming call attempt to seize the
same circuit at the same time. On loop-start analog lines this usually causes the two callers to be connected
because loop-start lines do not manage glare resolution. PRI COs, however, utilize glare resolution protocols
that define what the CO will do with a call if glare is detected. The IP Server 900
requires
that connected PRI
circuits be set to the
normal
(also called
standard
) protocol rather than the yielding protocol. This means that
the system will block the
outgoing
call
if glare is detected.
•
Incoming Hunt
— In order to help prevent glare, PRI providers will attempt to send calls down the PRI in the
opposite order that the phone system attempts to send them out. The IP Server 900 sends calls out in a
descending order, meaning the first call goes out channel 23. When ordering the PRI the service provider
needs to set the circuit to hunt in an
ascending
order, meaning incoming calls will start at
channel one
.
•
ISDN Bearer Capabilities
— This is the supported PRI feature set. The IP Server 900 supports
only
56K
voice
(CSV)
.