In addition, recent enhancements that allow
the creation of Layer-2 virtual private networks will usher in a range of new services
targeted at business customers.
Technology Description
The Data-Over-Cable Service Interface Specification (DOCSIS) is a Layer 1 and Layer 2
technology [1] standard that utilizes the IEEE 802.2 (Ethernet) Logical Link Control
(LLC) and the IEEE 802.3 Media Access Control (MAC) addressing scheme and similar
framing conventions. The remainder of the MAC layer functionality is markedly different
from IEEE 802.3 Ethernet and is tailored for the particular demands and capabilities
of the hybrid fiber-coax (HFC) cable plant.
Cable
modem Customer
premises
equipment
CMTS
Wide area
network
Cable
network
10/100/1000BT
Ethernet
802.11a/b/g wireless
DOCSIS 1.0/1.1/2.0/3.0 Gigabit ethernet
148 Chapter 6
The first version of the DOCSIS standard, DOCSIS 1.0 [2], was created as a proofof-
concept for high-speed access over the North American HFC cable network. In creating
the DOCSIS 1.0 standard, goals were kept fairly modest. Time-to-market and
interoperability amongst multiple vendors were the primary concerns, so the complexities
involved with implementing absolute state-of-the-art technology were purposefully
avoided.
Pages:
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383