Paradyne EAM2000-12 Frame Type, Line Code, Timing, Cyclic Redundancy Check Default, Local Default

Models: EAM2000-12

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Frame Type

NOTE Although all 31 channels continually run at 1,984 kbps, the Timeslot configuration for each port determines how many of the channels will be receiving data for that port. Ports configured to operate as fractional E1 lines require contiguous timeslots, as indicated in the table above.

Frame Type

Frame type is the E1 data encapsulation method. A frame consists of 248 bits (8-bit samples of each of the 31 E1 channels plus a synchronization bit) transmitted at a rate of 8,000 frames per second (1,984 kbps) across the E1 line.

Cyclic Redundancy Check (Default)

The Cyclic Redundancy Check (CRC) detects line errors and scrutinizes data integrity across the E1 line by appending a CRC character to the end of the data block. The character is a hexadecimal value calculated from the contents of each data block. The remote modem makes a similar calculation upon receipt of each data block and requests retransmission if there is a difference. CRC may be disabled on the EAM200-12 through Net to Net's Network Management System (NMS). For further instruction, refer to the Management User Guide for IP and Mini DSLAMs.

Line Code

Line code is the E1 mode of transmission. The following line code options fall within the International Telecommunication Union - Telecommunication Standardization Sector (ITU-T) G.703 Standards for Transmission Facilities.

High Density Binary 3 (Default)

High Density Binary 3 (HDB3) is used to accommodate the minimum ones density requirement in the European public network. HDB3 line coding helps prevent loss of synchronization between the EAM2000-12 and remote E1 modems by using bipolar violations to guarantee there will always be pulses in the line.

Alternate Mark Inversion

The Alternate Mark Inversion (AMI) mode of transmission simply alternates positive and negative pulses. It is typical, with AMI, for a link to encounter long strings of zeros, which can potentially cause loss of synchronization between remote units. Net to Net Technologies' products however, meet the European minimum ones density requirement internally such that, even with AMI, loss of synchronization is prevented between the EAM2000-12 and remote E1 modems as it is with HDB3 line coding.

Timing

Local (Default)

The transmit clock source will originate from an oscillator onboard the EAM2000-12.

Loop

The transmit clock source will originate from the remote E1 modem.

210-0000036 rev03

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Paradyne EAM2000-12 Frame Type, Line Code, Timing, Cyclic Redundancy Check Default, High Density Binary 3 Default, Loop