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Specifications and data, Wan interface specifications, Appendix a: specifications and data – ADC 500L User Manual

Page 69: Pr el im in a ry

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Megabit Modem 500L Installation Manual

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PECIFICATIONS

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ATA

WAN I

NTERFACE

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PECIFICATIONS

ADSL (Asymmetric Digital Subscriber Line)

Maximum transmission rate:

Downstream

Upstream

1.5 Mbps

512 kbps

Minimum transmission rate to sync 64 kbps

Rate-adaptive data rate resolution

32 kbps increments

Signal Format

DMT (Discrete Multitone) line code

Connector

RJ-11

ATM (Asynchronous Transfer Mode)

ATM Adaptation Layer

AAL5 (ITU I.363.5) - Supports encapsulation and
de-encapsulation of AAL5 Protocol Data Units (PDUs) for
convergence. Segmentation and Reassembly (SAR) layer
segments and reassembles AAL5 PDUs into ATM cells that are
48-byte SAR-PDUs.

ATM Layer

Attaches or strips the 5-byte header to the 48-byte SAR-PDU.
Performance is a maximum line rate of 17,812 cells per second
downstream and 2,189 cells per second upstream.

Cell Format

Format complies with ITU I.361 ATM cell format. Cell delineation
complies with ITU I.432 Cell Delineation and HEC. Cells are fixed
length (53 bytes), including 5 bytes of header and 48 bytes of
payload. Included in the header are the VPI and VCI number.

Virtual Circuit type

Permanent Virtual Circuit (PVC) per ATM forum UNI version 3.1.

Maximum Virtual Circuits

Three virtual circuits, with one that is actively connected to a
service provider; encapsulated as PPP.