Zhone EtherXtend 3300 Series, Руководство пользователя

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Zhone EFM features
EtherXtend User’s Guide
27
Loop bonding
Ethernet loop bonding refers to a technology where multiple physical SHDSL
lines are grouped together to provide greater bandwidth potential over a single
logical connection. The WAN connection terminates into a single Ethernet
connection, providing a single connection to the end user.
However multiple lines aggregate on the WAN to provide higher bandwidth.
This enables carriers to provide greater distances for higher bandwidth
services, for example, IP television, VoIP, and other converged services.
In DSL loop bonding, two or four copper pairs are utilized to yield up to 8x
the bandwidth at any given distance. This allows extremely long local loops to
deliver high-speed DSL. For example, while SHDSL only supports 144 Kbps
at 25,000 feet, four SHDSL lines together would provide 576 Kbps or just
over .5 Mbps. The loop bonding aspect of the connection is invisible to the
consumer who realizes an increase in access speed.
The following table shows the data rates that bonded loops can produce.
While the total achievable distance is not increased through loop bonding, the
maximum bandwidth that can be achieved at any distance is increased,
making even very long DSL deployments capable of high data rates.
Table 4: Selected data rates (in Kbps) realized through bonding loops
Distance
(feet) CO-to-CPE
(1 Pair) CO-to-CPE
(2 Pair) CO-to-CPE
(4 Pair) CO-to-CPE
(8 Pair)
5,000 5,704 11,408 22,816 45,632
7,000 5,704 11,408 15,936 28,800
9,000 3,856 5,792 9,536 18,560
12,000 2,192 4,384 7,488 10,368
15,000 1,040 2,080 3,392 5,248
18,000 464 928 1,856 3,200