When Does This Solution Not Fit?
The use of IP over Ethernet in subscriber access applications eliminates unnecessary
network layers. The elimination of network layers reduces the number of network elements
in a network, and that reduces equipment costs, operational costs, and complexity.
At the edge of the first mile, simpler architectures are always easier to manage. In the
first mile, native Ethernet on copper or fiber will offer significant cost-performance
advantage over competing technologies. These IP/Ethernet networks will, of course, coexist
with TDM and SONET/SDH services. For example, for business customers, T1
and fractional T1 might be provisioned over Ethernet on optical fiber. Also, in many
cases, the service provider might backhaul data, voice, and video to a SONET/SDH
network.
Metro access for business and residential subscribers with EFM technologies is
one critical component of the larger metro solutions portfolio available currently on
the market. The three EFM topologies being defined by IEEE 802.3ah will complement
each other. Ethernet over VDSL on copper is the best fit for established neighborhoods,
business parks, and MxUs because it can reuse the existing voice-grade,
twisted-pair copper cable.
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