Triple-Play Service Deployment

Chapter 9: Troubleshooting High Speed Data Service
Providers typically offer service level agreements (SLAs) for high
speed data service only for business class customers. Yet with
consumers becoming increasingly demanding, it is likely that
business-style SLAs may soon migrate to residential customers. In
the meantime, some service providers already measure their
performance on residential accounts by their ability to meet
typical business level SLAs with a particular focus on throughput.
Understanding xDSL
Delivery of high speed data service over copper is possible largely
due to advances in digital subscriber line (DSL) technology.
ADSL/2/2+ places increased demands on physical loop performance
to enable service delivery at data rates necessary for triple-play
services. VDSL technologies further increase loop performance
requirements.
ADSL
Delivery of ADSL-based data services requires a single copper pair
to carry a standard voice circuit as well as the data service. Three
information channels are created: a plain old telephone service
(POTS) channel for voice, a medium speed upstream channel, and
a high speed downstream channel.The POTS channel is separated
from the ADSL channels via a passive, low-pass/high-pass filter
that separates the low frequency POTS signals from the high
frequency ADSL signals. The splitter also protects the DSL signal
from POTS signal transients originating from events such as onhook
and off-hook and ring tones.
ADSL service may be installed without a splitter by using micro
filters in-line with the phone jack at each telephone device,
enabling the customer to install the customer premises
equipment (CPE). Data rates depend upon several factors
including length of the copper pair, wire gauge, presence of
bridged tap, proper bonding and grounding and the overall
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