Digital Trunk Acceptance Test

Need for Digital Trunk Acceptance Test:

 Once a T1 / Trunk is installed between A – point and Z – point, then in order to check , whether the T1 / Trunk is capable to pass the digital signals as requested by the customer. These tests can be performed when SAS Feature Group D Access is ordered from the service provider and delivered via a digital switch, on digital facilities, and without digital to analog conversion on the service provider portion of the circuit. In cases where the IC has a D/A conversion, the final choice of tests shall rest with the IC.

Digital Acceptance Tests:

A trunk is tested for the digital transmission facility between the AT and EO where it is newly installed. There is no need to test the T1 or Trunks which exist and are in service.  The acceptance test of the Digital transmission facility for FG-D has three steps, which are described below.

Ø      One signaling/operational test per trunk.

Ø      One 1004 Hz loss and one C-Notch Noise test per trunk group per di-group in both directions of transmission.

Ø      Error Ratio (BER) test in each direction of transmission using compatible Quasi / Pseudo Random Signal Source.

Acceptance Criteria:

v      Acceptable BER should be 10(7) or better for a period of five minutes.

v      The test should be made between the EC DSX, closest to the service provider digital service, and the first IC DSX.

v      If the DS-1 facility is connected to a DS-3/HC-3 service, in lieu of cooperative acceptance tests, the service provider will provide a loop-back at the DSX-1 closest to the service provider digital switch toward the MUX and notify the IC the loop-back is in place. The IC can verify the integrity of the DS-1 through the DS-3/HC-3. BER parameters apply.

v      The test shall be performed at a mutually agreed upon time during normal business hours, and generally should be performed prior to facility turn-up for service.

These digital test procedures are consistent with industry agreement for Installation and Maintenance responsibilities for Feature Groups B, C and D to verify the capability of installed T1 / Trunk for their digital transmission.

Key Words:

LATA – Local Access and Transport Area

LEC – Local Exchange Carrier

IC – Inter Exchange Carrier

POT – Point of Termination

CAC – Carrier Access Code

ANI – Automatic Number Identification

EO – End Office

CCS – Common Channel Signaling

SS7 – Signaling System 7

IG – Interface Group

PSDS – Public Switched Digital Service

ISDN – Integrated Services Digital Network

DEOT – Direct End Office

NANP – North American Numbering Plan

FPOS – First Point of Switching

NC Code – Network Channel Code