Help Desk and
Frequently Asked Questions

ISDN/ADSL Frequently Asked Questions

What is ISDN?

ISDN (Integrated Services Digital Network) is a system of digital phone connections which is compatible with the existing (analog) telephone system. ISDN customers can use their phones to make conventional (analog, dialup) voice connections. In addition, ISDN customers can make high-speed digital data connections with other ISDN-capable telephone customers.

How Does ISDN work?

ISDN allows data to be transmitted and received around the world using end-to-end digital connectivity. With ISDN, voice and data are carried by 64Kbps bearer channels (B channels). Multiple B channels can cooperate to provide higher data rates. Common ISDN installations can easily be configured to use two (2) B channels, providing a true data rate of 128Kbps. In all ISDN installations, a data channel (D channel) handles control signalling at 16 kbps or 64 kbps, depending on the service type.

What Does ISDN Do For ME?

There are two basic types of ISDN service: Basic Rate Interface (BRI) and Primary Rate Interface (PRI). Most individual and small business ISDN service consists of BRI Circuits. A BRI Circuit consists of two 64 kbps B channels and one 16 kbps D channel for a total of 144 kbps. With BRI service, two people can be using the B Channels for voice (conversations) simultaneously. Or a single 128Kbps Internet connection can be made using both B Channels. Or a 64Kbps Internet connection can be established using one B Channel, while the other B Channel is available for voice connections. ISDN is very flexible. It can be configured to connect to the Internet at 128Kbps and, if an incoming (voice) call arrives, dynamically release one B Channel (slowing the Internet connection to 64Kbps), freeing the other B Channel to handle the voice call.

Also, ISDN is an excellent medium for video conferencing, whereas the current Internet is not. ISDN direct-connect can provide very pleasing video conference capabilities, independent of any Internet connection.

Is ISDN Standardized?

Yes, ISDN conforms to a recognized, international standard. If you elect to install ISDN, you will be able to make high-speed data connections worldwide.

How Much Does ISDN Cost?

In Bowling Green, ISDN currently carries a per-minute charge for data transfer, making it very expensive for most applications. However, in August 1998, Verizon filed for "flat-rate" ISDN with rates in the $70-$80 per month range for the residential customer. We expect favorable action by PUCO in the near future; at that time, ISDN will become very affordable, particularly for people currently paying for two conventional phone lines.

When these rates are approved, you will be able to get two phone lines (3 if you count the D Channel that can handle a FAX) for $70-$80 per month. This would provide a dynamic mix of the options detailed above. Note that 128Kbps users should expect their WCIC subscription price to increase appropriately.

What is ADSL?

As implemented by WCIC and Verizon, ADSL (Asymmetric Digital Subscriber Line) provides a dedicated (24x7) Internet connection and a single analog phone line. Each ADSL subscriber has an ADSL modem ($300 purchase or $12/month) connected to Verizon's incoming telephone line. The ADSL Modem has an RJ-11 jack into which you can plug a standard telephone (or the phone wiring for your entire house) and an RJ-45 jack providing a 10BaseT ethernet connection to WCIC Internet. You simply cable from the ethernet card in your computer to the ADSL modem's RJ-45 port, and you are on the Internet 24 hrs/day, 7 days per week (no dialup necessary).

How Does ADSL Work?

ADSL provides an Ethernet link between your computer and WCIC's Ethernet LAN that handles the Internet traffic. It also provides one (1) voice-grade Plain Old Telephone System ("POTS") line for your use. Your computer is assigned a permanent IP address on the Internet and, unless you powerdown your computer, you have a 24x7 "Internet presence."

ADSL was developed at Stanford University's Electrical Engineering Department. Its function depends heavily on the quality of the existing (copper) wires between you and the phone company's Central Office ("CO"), and the distance from you to the CO. An ADSL customer near the CO who has "high-quality copper" should have no problem running at 1.544Mbps. Another ADSL customer 3 miles from the CO with poor quality copper may be limited to 256Kbps. WCIC will arrange telephone line testing for prospective ADSL customers. Be aware that one possible result of the testing is that your phone lines are not suitable for ADSL.

How Much Do ADSL Circuits Cost?

The "A" in ADSL stands for asymmetric, meaning that the speed from the Internet to you ("downstream") may be different from the speed from you to the Internet ("upstream"). ADSL circuits from Verizon are priced by speed. The current offerings include:

	Downstream/Upstream	ADSL Phone Line Cost
	256Kbps/ 64Kbps	$ 35/month
	384Kbps/384Kbps	$ 55/month
	768Kbps/768Kbps	$ 70/month
	1.544Mbps/768Kbps	$100/month

Because of the nature of the Internet and the various Web Servers that you may elect to access, you may not observe the speeds listed above. In fact, many people find it difficult to detect the difference between the 384Kbps ADSL link and the 1.544Mbps ADSL link.

In addition to the ADSL phone line cost, there will be an appropriate increase in your WCIC subscription fees.

Is ADSL Standardized?

Not at this time. Verizon has elected to utilize equipment manufactured by Orckit, while Pacific Bell is using Alcatel equipment. ADSL equipment from these two companies are, in general, incompatible. The International Telecommunications Union ("ITU") plans to ratify the "G.Lite" (spoken "gee dot light") Standard by Summer 1999. If things go according to plan, by mid-1999 many personal computers will be shipping with built-in G.Lite modems.

Which is Better, ISDN or ADSL?

That depends on a number of factors. One factor is the quality of the telephone lines between you and the CO. Many Bowling Green area users will simply not be able to get ADSL, due to distance/line quality considerations. We hope that many subscribers in this group will be able to qualify for ISDN. Hence, there exists a group of subscribers for whom ISDN is the only technology available to provide increased Internet access speeds.

Another factor that warrants consideration are your useage patterns. If you frequently use two or more telephone lines for voice connections, ISDN may be attractive to you. This is especially true if you typically connect to the Internet several times a day but for only an hour or two. An ISDN BRI Circuit not only supports 128Kbps Internet access, it can also support two telephone connections (voice) and a FAX connection.

And there is the factor of speed. If you need the highest speeds and your phone line quality and location qualify you for ADSL, then ADSL is probably for you. This is also the case where a dedicated, 24x7 Internet connection is necessary.

Note that ISDN offers the option of high-speed direct-connect to remote networks other than the Internet. This could be important for "Intranet" access and some special-purpose applications like video conferencing.

Where Can I Get More Information?

For general ISDN information, Open Communication Networks, Inc. has a very good, relatively non- commercial ISDN site at: http://www.isdn.ocn.com

For general ADSL information, the ADSL Forum (Fremont, California) has a good ADSL site at: http://www.adsl.com

Verizon has an excellent ADSL area on their web site at: http://www22.verizon.com/forhomedsl/channels/dsl/

For specific help in configuring an ISDN or ADSL system for your needs in Wood County, Ohio, contact WCIC at help@wcnet.org or call 419-354-6013.

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