1. What is ISDN?
2. How fast is ISDN?
3. Is ISDN right for me?
4. What does ISDN cost?

1. What is provisioning?
2. How is ISDN configured?
3. What hardware does my computer need for ISDN?
4. How will I interface with the telephone network?
5. What kinds of wiring and jacks will be installed?
6. Can I connect multiple devices to an ISDN line?
7. I have a network and want ISDN access for it. What do I need?

1. How do I order ISDN?
2. What happens after I place my order?
3. How will I be billed?
4. What if I have other questions not covered here?

Introduction to ISDN

1. What is ISDN?

ISDN (integrated services digital network) is a phone technology that provides digital service over existing copper wiring. ISDN has been on the market for many years, but has only recently grown popular due to the limitations of analog modems and the rise of Internet usage. Most of the existing telephone network is already digital. The only part of the network that typically remains analog is the section that runs from the local exchange to your house or office. ISDN makes that final leg of the network digital.

ISDN typically divides the telephone line into three digital channels: two `B' channels and one `D' channel, each of which can be used simultaneously. The B channels are used to transmit data. The D channel does the administrative work, such as setting up the call and communicating with the telephone network. With two B channels you can make two calls simultaneously.

2. How fast is ISDN?

ISDN service is provided in increments of 64K. Users of this technology typically connect via single (64k) or dual (128k) channel.

3. Is ISDN right for me?

ISDN is a circuit-switched service, which means it is only connected when it is being used. If you need a continuous connection (eg. for running a web server), you can purchase a dedicated ISDN connection. ISDN is a very powerful and flexible service, providing support for solutions as diverse as computer connectivity, burglar alarm monitoring, and virtual PBX telephone services.

4. What does ISDN cost?

ISDN rates vary according to your phone company. ISDN pricing typically has two components: monthly charges for the line and usage charges associated with the use of the ISDN line. Additionally, there is usually an installation charge to have the ISDN line installed. Here is Seanet's monthly ISDN charges.

Installation Questions

1. What is provisioning?

Provisioning is a term used by the phone company for the configuration of your line on the their end. A normal analog phone line comes with a few options like "call waiting" or "caller ID", but it is not necessary to choose any of them in order for the phone company to give you access to those services. An ISDN line, on the other hand, has many options and choices which must be defined in order for the line to function.

2. How is ISDN configured at my end?

In addition to the ISDN line configuration that is handled by the phone company, you will need to to configure the equipment on your end. You need to know three pieces of information to make your ISDN service work with your computer:

Switch type - Most ISDN hardware adapters need to know the type of switch to which they will be connecting. The switch type simply refers to the brand of equipment and software revision level that the phone company uses to provide you with ISDN service.

Phone numbers - The second piece of information you need is your phone number or numbers. In some cases, each B channel on an ISDN line has its own number, while in other cases both B channels share a single phone number. Your telephone company will tell you how many numbers your ISDN line will have. Separate numbers may be useful if you plan to take incoming calls on your ISDN line.

SPID(s) - Service Profile Identifier(s) - The last type of information is the SPID (Service Profile Identifier). The SPID usually consists of the phone number with some additional digits added to the beginning and end. The SPID helps the switch understand what kind of equipment is attached to the line, and if there are multiple devices attached, helps route calls to the appropriate device on the line.

3. What hardware does my computer need for ISDN?

There are two types of ISDN hardware adapters:

Internal ISDN modems are cards that you put inside your computer. In order to install an internal adapter, you need a slot free in your computer that supports the same type of bus (e.g., ISA, EISA, PCI) as the card you want to install. You will also need to install software so that the internal adapter can communicate with your computer's operating system.

External ISDN modems/routers connect through a port on the back of your computer. External ISDN adapters are easy to install and do not require any special software. External ISDN adapters look just like a modem to your computer (some manufacturers even call them "ISDN modems"). Communication programs control the external ISDN modem just like they control an analog modem (typically with AT commands). There are certain limitations imposed by the ports you plug an external adapter into on your computer that you should be aware of when choosing this type of ISDN device. For instance, most PC serial ports will not transmit information faster than 115k, which is less than ISDN's maximum data speed of 128k. These serial ports impose overhead on the transfer of information between the PC and the external adapter, further slowing data speeds.

4. How will I interface with the telephone network?

Once you have ISDN service, you need to know which ISDN interface your equipment expects. There are two ISDN interfaces. The U-Interface carries ISDN signals over a single pair of wires between your location and the phone company's central office. This interface is designed to carry ISDN signals over long distances. The Subscriber/Termination (S/T) Interface uses two pairs of wires to deliver the signal from the wall jack to your ISDN adapter or other ISDN equipment.

If your equipment supports the S/T-Interface, you'll need to get a device known as a Network Termination 1 (NT-1) which converts between the U-Interface and the S/T-Interface.

Some ISDN adapters sold in North America connect directly to a U-Interface. If your computer is the only equipment to be connected to an ISDN line, this type of adapter is the easiest to install. Manufacturers may describe this feature as a "built-in NT-1" or simply as a U-Interface ISDN adapter.

5. What kinds of wiring and jacks will I need?

ISDN service from the phone company officially ends at what is called the demarcation point ("demarc") -- usually just inside the building. You are responsible for the installation of "inside wiring" from the demarc to your ISDN equipment including the wall jacks. The phone company or an electrical contractor can install and maintain the inside wiring for an additional charge. Direct wiring between the ISDN wall jack and the demarc (also known as a "home run") is recommended.

If you are connecting only your computer to the ISDN line, the wiring requirements may be very simple. Many homes and offices are wired with extra sets of telephone wires and one of those sets can be used for your ISDN line. There are a number of possible wiring pitfalls to be aware of: 1) your "extra" wires may already be in use for analog line(s), 2) your "extra" wires may be in use for powering lighted phone buttons, 3) your "extra" wires may not be connected directly to the demarc, the wiring may be "daisy-chain" rather than "home-run."

There are two types of jacks associated with ISDN: RJ11 (the standard analog phone jack which has 4 wires and connects the NT-1 to the wall), and RJ45 (this jack is slightly wider than the RJ11, has 8 wires and connects the NT-1 to the ISDN adapter).

6. Can I connect multiple devices to an ISDN line?

It is possible to connect up to eight devices to a single ISDN line. These devices can include network routers and bridges, Group 4 ISDN fax machines, and ISDN telephones or traditional analog telephone devices. ISDN is intelligent enough to arbitrate the use of the two B channels between these devices (up to two devices can be in use simultaneously) and to route incoming calls to the appropriate device.

You may also connect several ISDN devices to a single ISDN line. For example, you might want an ISDN adapter in your computer, an ISDN telephone to make voice calls, and a Group 4 ISDN fax machine all connected to the same ISDN line. Incoming data calls would go to the computer, voice calls to the telephone, and fax calls to the fax machine. To support this configuration, you would need an NT-1 that supports multiple S/T Interface connections. Each device would be connected to the NT-1. Each device would also need its own Service Profile Identifier (SPID) to ensure the phone company can route calls to the appropriate device.

In addition to ISDN devices, some NT-1s or ISDN adapters also support analog telephone devices like phones, data modems, Group 3 fax machines and answering machines. The NT-1 or the ISDN adapter converts the analog signal into ISDN and vice versa.

7. I have a network and want ISDN access for it. What do I need?

It is possible to connect an ISDN line to a LAN so all the computers on the LAN can share the ISDN line. This requires an ISDN network bridge or router.

Ordering ISDN from Seanet

1. How do I order an ISDN account?

You first need to place an order for the ISDN line with your phone company (usually Verizon or Qwest). When the line has been installed you are ready to order the ISDN account from Seanet. Call Seanet sales at (206)343-7828 or (800)973-2638 to get your account started.

2. What happens after I place my order?

After you place your order, one of our technical support representatives will walk you through the steps necessary to configure your computer to connect to Seanet and retrieve e-mail and newsgroups. Once that's done, you're ready to go!

3. How will I be billed?

Seanet offers you the choice of being billed via credit card or invoice on a monthly, quarterly, or semi-annual basis. If we bill you quarterly, you'll receive a 5% discount. If we bill you semi-annually, you'll receive a 10% discount. If you choose paper invoice billing, there is a charge of $2 per invoice. Bills are due when received.

4. What if I have other questions not covered here?

You may call our sales department at (800)973-2638 or (206)343-7828 for more ISDN information or you may email sales.