Line Code; Bipolar With 8 Zero Substitution (Default; Alternate Mark Inversion; Configuration And Management - Net to Net Technologies TIM1500 User Manual

2.5 Line Code

Line code is the T1 mode of transmission. The two line code options for the TIM1500 both fall within
the International Telecommunication Union - Telecommunication Standardization Sector (ITU-T)
G.703 Standards for Transmission Facilities.

2.5.1 Bipolar with 8 Zero Substitution (default)

Bipolar with 8 Zero Substitution (B8ZS) line encoding uses bipolar violations to guarantee the
presence of pulses in the T1 line thereby helping to prevent loss of synchronization between
the TIM1500 and remote T1 equipment. B8ZS accommodates the minimum ones density
requirement in the North American public network.

2.5.2 Alternate Mark Inversion

Alternate Mark Inversion (AMI) alternates positive and negative pulses across the T1 line.
Although AMI links typically encounter long strings of zeros which can potentially cause loss of
synchronization between T1 units, Net to Net Technologies' T1 products meet the North
American minimum ones density requirement internally such that, even with AMI, loss of
synchronization is prevented between the TIM1500 and remote T1 equipment, just as it is with
B8ZS.
2.6 Speed
All T1 lines consist of 24 channels (timeslots) that continually run at 64 kbps for a collective
bandwidth of 1,536 kbps. Timeslot configuration dictates how many of the channels for each port
will actually receive data. Ports configured to operate as fractional T1 lines require contiguous
timeslots as indicated in the chart below.
Single Line T1 Bandwidth (kbps)
TIMESLOTS 1 - 24
COLLECTIVE
1,536
SPEED

3.0 ADDITIONAL INFORMATION

3.1 Configuration and Management

Once the TIM1500 has been installed, all parameter settings are software selectable via Command
Line Interface (CLI), Simple Network Management Protocol (SNMP) and/or Net to Net's Network
Management System (NMS) dependent upon the multiplexer uplink module (MUM) model installed
in your IP DSLAM. Refer to Net to Net's NMS Management User Guide
( http://www.nettonet.com/support/docs/210-0000048
( http://www.nettonet.com/support/docs/210-0000052
management and interface module parameter configuration.
210-0000053 rev02
1 - 21 1 - 18 1 - 15 1 - 12
1,344 1,152 960 768
TIM1500 User Guide
Default bandwidth utilizes
1 - 9 1 - 6 1 - 3 all 24 timeslots for a speed
of 1,536 kbps.
576 384 192
) and/or CLI Management User Guide
) for further instruction regarding IP DSLAM
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