Frequently Asked Questions

What is T1?
What is DSL?
What is ADSL?
What is SDSL?
What IDSL?
How do T1 and DSL Internet Access Compare?

What is T1?

T1 is based on a industry standard technology used to access the Internet at speeds from 384K to 1.5M. T1 is a far-reaching, fast access solution designed for businesses with high bandwidth needs.

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What is DSL?

DSL or Digital Subscriber Line uses standard voice grade lines to provide Internet access at speeds from 128K to 1.5M. Because DSL uses voice grade lines, the end user location must be within 3 miles of the nearest telephone central office. DSL is a relatively low cost solution designed for small-to-medium offices or home office/home users who do not require guaranteed high availability.

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What is ADSL?

ADSL stands for Asymmetrical Digital Subscriber Line. This means that the speed is different in both directions. For example, a common DSL package includes a speed options of 768/128 Kbps. This means the transfer speed down is 768 Kbps (kilobytes per second) whereas the speed up is 128 Kbps. ADSL is ideal for email and general surfing. However, the slower upload times may negatively impact VPN performance for remote users.

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What is SDSL?

SDSL stands for Symmetrical Digital Subscriber line. Unlike ADSL, the speeds for Symmetrical Digital Subscriber Lines are synchronous. So regardless of the speed chosen, transfers will be the same in both directions.

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What IDSL?

IDSL is basically ISDN. IDSL is ideal for those customers who are too far from the central office to obtain either ADSL or SDSL services. The speed on this service is symmetrical, but it is fixed at 144 Kbps.

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How do T1 and DSL Internet Access Compare?

FeaturE	T1	DSL
Main Advantage	Quality	Cost
Target	Organization with mission-critical need for high-speed connectivity, including web hosting and company-wide access.	Small businesses and residential users requiring cost-effective alternative for high-speed access.
Speed	Speed 384k - 1.5mb (at all times)	128k - 2.0mb (speeds and synchronous transmission is not guaranteed)
Government Regulation	Regulated -- State and FCC regulations mandate minimum cost escalation, defined quality levels, and customer service responsiveness.	Unregulated -- There are no State and FCC regulations in place. Circuit cost escalations, defined quality levels, and customer service responsiveness are at the discretion of Verizon or other local Bell and the third party DSL provider.
Speed vs. Distance	Guaranteed fixed speeds, independent of distance.	Speed is dependent on distance from telco central office - the farther away, the slower the speed. Synchronous transmission cannot be guaranteed.
Distance Limit	No limitations on distance from CO.	Limited to 3.5 miles from CO.
Circuit Availability	T1 circuits are widely available.	Limited availability -not all towns served.
Physical Circuit	T1 circuits are engineered for digital data transmission and may be delivered via fiber optic	DSL connections are made from voice-grade copper telephone circuits. Fiber, bridges or taps on circuit will prohibit DSL.
Connection	T1 service offers private point-to-point dedicated connection between the customer and Tier 1 backbone network -- there is no middleman.	DSL is provided through a third-party vendor and is connected via a shared, switched ATM network. A number of customers are aggregated at multiple single connection points (DSLAM in each DSL Central office). Each aggregation point is a potential point of failure.
Installation	T1 circuit installation process is predictable averaging 40 business days.	DSL installation is uncertain and can be problematic, ranging from 40 days to 90 days plus. At least 10 percent of orders will never be installed due to telco issues.
Circuit Repairs	FCC mandates a one-hour repair response from telco providers, once a trouble ticket on T1 circuits is opened.	DSL connections are treated as voice-grade circuits. This means the telco will not respond to trouble tickets until the next business day.
Pricing	Pricing Ranges from $399 to $649 PLUS local loop (direct telco connection from you to Verizon Central Office)	Ranges from $139.99 - $399.00

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