PairGain 500L, User Manual

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Megabit Modem 500L Installation Manual 61
PR
EL
IM
IN
A
RY
A
S
PECIFICATIONS AND
D
ATA
WAN I
NTERFACE
S
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.