Recommendations For North American Ls Trunks; Recommendations For Uk Ls Trunks; Ls Trunk Impedance Characteristics - Mitel 3300 ICP Hardware Technical Reference Manual

C 2
HAPTER

Recommendations for North American LS Trunks

The information in the following table is based on North American transmission specifications and is
provided for North American installations. Other regions or countries will have similar specifications; refer
to region- or country-specific specifications when installing product in regions other than North America.
For best performance, analog trunks should meet or exceed the "acceptable" values in the following table.
If an analog trunk fails to meet the "acceptable" values the issue should be addressed with the service
provider.
The values specified for Circuit Noise, Power Influence and 3 kHz Flat Circuit Noise assume a transmis-
sion level of 0 dB. For interface transmission levels other than 0 dB, the specified values should be shifted
by a value that corresponds to the difference between the transmission level at that interface and 0 dB.
Recommended Transmission Specifications for North American LS Trunks
Table 2.21:
Circuit
Transmissi Noise
on Quality (dBrnc)
Acceptable ‹=20
Marginal 20-23
›25
Unacceptab
le
dBrnC: Decibels above Reference Noise with C-message weighting.
dBrn3KHz: Decibels above Reference Noise with 3 KHz flat noise weighting.

Recommendations for UK LS Trunks

This following information is only relevant for installations in the UK:
When connecting the 3300 ICP to Local Exchange lines via LS trunks it is important that the correct
•
line type be used.
The installer or system administrator should request that the Telco (e.g. BT), or carrier, provide trunks
•
that are compatible to System X line type '0' (Subscriber lines) or line type '3' (business PBX/PABX
lines).
Both types of lines will work satisfactorily with the 3300 ICP, however line type '3' is the preferred line
•
type for connecting a PBX/PABX.

LS Trunk Impedance Characteristics

The following tables provide the impedance values for each Balance Network Setting option (CO Trunk
Circuit Descriptor form) depending on the country variant of the system.
: "Non-IP" impedance values apply to trunks that are not connected to an IP port; and "IP" values
NOTE
apply to trunks that are connected to an IP port.
F U
IELD PGRADEABLE AND
2 kHz Flat
Circuit Power
Noise Influence
(dBrn3kHz) (dBrnC)
‹=40 ‹=80
40-60 80-90
›60 ›90
R C
EPLACEABLE ONTROLLER
Circuit
Balance Circuit
(dB) Loss (dB)
›=60 <=6
50-60 6-8
‹50 >8
M (AX, MX , CX II)
ODULES E I
3300 ICP C
ONTROLLERS
Loop
Current
(mA)
›=23
18-23
‹18
34