Frequently Asked Questions:
ISDN Service
The CoreComm FAQ (list of Frequently Asked Questions) answers questions that are frequently asked of
CoreComm's technical support department.
This document is designed to answer a number of frequently asked questions about ISDN. To a beginning user, getting information on ISDN often seems daunting because there isn't much information available, and what information there is, often it's quite cryptic. While this document has some technical information, it is written with the intention of taking the beginning ISDN user step-by-step through what they will need to know when getting connected with ISDN.
What is ISDN?
ISDN stands for "Integrated Services Digital Network", which isn't very descriptive. Basic Rate Interface ISDN (known as BRI ISDN, or just ISDN for short) is a phone line that carries digital signals instead of analog signals (like your standard telephone line does now). Because the information is carried along the lines as a digital signal, data can be transmitted much faster.
Doesn't an ISDN line use expensive fiber optics, or something otherwise different from a normal phone line?
No. An ISDN line is physically exactly the same as a normal phone line -- a twisted-pair copper wire. In many cases, a phone line that has been used as a normal telephone line can be used as an ISDN phone line as well.
Do I need to have an ISDN line instead of a normal phone line to use your ISDN service?
Yes. While the physical wire itself is the same as a normal phone line, the hardware that it connects through at the phone company is quite different.
How fast is an ISDN line?
A standard ISDN line carries two separate channels of information, known as B-channels. Each B-channel can operate as fast as 64kbps (more than twice as fast as a normal 28.8kpbs modem). If you use both channels to connect with CoreComm, the speed of the connection would be 128kbps, almost two and a half times faster than a 56kbps modem. Not only that, but because ISDN service is digital, doesn't suffer from line noise potentially slowing it down like on analog modems.
Do I need a special modem to call CoreComm through an ISDN line?
Yes, you will. ISDN modems (called terminal adapters or TA's) are different from the modems typically used to connect computers across analog phone lines. You can expect to pay between $200 and $400 for a good ISDN modem. More expensive TA's are available, but the features offered by these modems are often not needed by the average customer.
Does CoreComm recommend a specific ISDN modem?
The 3Com Impact IQ is a very good adapter, works very well with our system, and can be purchased for less than $250. Another worthy competitor is the Netopia ISDN modem. Both are as easy to set up as standard analog modem.
Be sure to get an ISDN modem that has an "internal NT1". An ISDN connection needs to go into a device called an NT1 in order to work correctly. Many units have them integrated with the modem. Also, if you're interested in doing 128kbps, make sure you choose an ISDN adapter that supports Multilink PPP. If you don't get an adapter that does Multilink PPP, your maximum speed on CoreComm's system will be limited to 64kbps.
In general, avoid ISDN adapters that require the use of a network card or other bridge. Such units can be painfully difficult to install, are very expensive, and generally do not offer features that a dial-in PPP user would need when connecting to the net. Such ISDN adapters also do not have internal NT1s, meaning that you would have to buy an NT1 unit separately to use them, which is a pricey proposition.
Can I use a standard phone to talk over an ISDN line?
You bet! Many ISDN modems (such as the previously mentioned 3Com Impact IQ) come with phone jacks that allow you to plug in your phone, fax, and standard modem and use the ISDN line just like a normal phone line. An ISDN modem that has this feature is typically described as having "POTS ports", or "Plain Old Telephone Service ports".
You can not simply plug in your normal phone into an ISDN line, however -- you should make sure that the ISDN modem you choose comes with POTS ports.
Also, when you order the ISDN line from your phone company, be sure to ask for "voice over data" to allow your ISDN line to be used in this way.
Can I talk on the phone and be on the Internet at once with a single ISDN line?
Absolutely! That's part of the magic of ISDN: since both B-channels can be used for different purposes, you can use one to talk on the phone (assuming that your ISDN modem has POTS ports) and use the other channel to go on-line. This will however temporarily limit your bandwidth to 64kbps since you will only be using one B-Channel for the Internet. Most TA's have the ability to automatically resume the Internet connection on your second channel after you're done talking.
Certain ISDN Adapters are capable of some neat tricks. For example, Some will disconnect the second B-channel if a call comes in. That means, if you log into our system with both channels (to surf the net at 128kbps) and a call comes in on the ISDN line, the Adapter will drop one of the B-channels (bringing your Internet connection down to 64kbps) and ring the phone that's connected to your Adapters POTS ports. When you hang up, the Adapter will automatically bring you back to 128kbps on the Internet. Consult a salesperson when looking to purchase your ISDN Adapter if you want this feature, to make sure you get an ISDN modem that is capable of this.
Can I call a normal telephone number on an ISDN line? Can a person with a normal phone call my ISDN line?
Yes. A normal telephone hooked up to an ISDN modem's POTS port works just like a normal phone. If you had a phone hooked up to your TA, and someone would call your ISDN number, it'll ring just like on a normal line (provided you do have Voice-Over-Data on your ISDN line). Outbound calls also work exactly the same as if it were a normal, analog line.
How much does the phone company charge for ISDN service?
The cost of the ISDN varies from location to location. Typically, there is an installation fee, a monthly fee, and a usage fee. Some usage fees might be per minute, and in other areas, the fee could be per call (where the amount of time the call lasts is irrelevant). Contact your local phone company for pricing information.
If you get an ISDN line from your phone company, and want to use it for an Internet connection and for making voice of fax calls, make sure you tell them you want your ISDN line to be usable both for voice and data.
Should I have both a standard phone line and ISDN, or just ISDN?
Most ISDN users have both an analog line and ISDN line. You need to have an ISDN modem powered up to talk over an ISDN line with your normal phone. If there is a power outage, you'll lose your phone service. As a safety consideration, it's best to keep both lines.
How do I order ISDN service from the phone company?
Call your phone company and ask to be set up for an ISDN line.
When ordering your ISDN line, be sure to specify that you want both voice and data over the same line if you want to be able to do voice communications on the ISDN line as well as connect with our system.
Some phone companies will offer deals where they will include an ISDN terminal adapter with the purchase of an ISDN line. While this sounds like a great deal, be careful of the kind of ISDN adapter they are offering. Occasionally, they will offer an inexpensive ISDN modem that may be prone to problems, or not have all the features you need. A quick search on the Internet should tell you all you need to know about the particular ISDN Adapter they are offering.
How much does dial-up ISDN access to CoreComm cost?
We have a number of different ISDN plans available.
Also, please go to our Local Access Numbers page to see if we have ISDN available in your area.
Note: If you plan on running a server over an ISDN line, or need an Internet connection 24 hours a day, 7 days per week, you will need a dedicated line. Please refer to our Business Services Dedicated Access section for more information.
How much does a dedicated, 24hr/day ISDN connection cost?
A dedicated connection requires two dedicated B-channels, an ISDN adapter at our end, and a single static IP address. Pricing and information on ISDN, and other available dedicated connection types, can be obtained by calling our Business Services department at 1-888-747-4638, or by completing our Business Sales Inquiry Form.
Where does CoreComm offer ISDN service?
Because we are always adding ISDN access to more locations, we ask that you call our Customer Service department at 1-888-747-4638 or visit our Local Access Numbers web page to obtain the most up-to-date list.
As always, before using any CoreComm local access number, please check with the operator (dial 0 on a phone attached to the line you will be calling from) to ensure that the new number will be a local call from your business or residence. CoreComm is not responsible for any long distance charges incurred when using this service.
How do I sign up for ISDN service with CoreComm?
Yu can sign up online or call our Customer Service department at 1-888-747-4638. Their hours are:
Customer Service
Hours of Operation |
| Monday - Friday |
8am - 11pm |
| Saturday - Sunday |
8am - 8pm |
| Times Listed are US Eastern Time |
What kind of software do I need for ISDN?
It generally depends on which ISDN adapter you get. An adapter like the 3Com Impact IQ works fine with any PPP software that supports PAP authentication (Windows 95/98/NT, Macintosh, Trumpet, Chameleon, and OS/2 all support PAP).
Some adapters, known as routers, use a network card as a bridge, and will require network drivers in order to run. Those drivers would likely be included with the network card purchased to work with the adapter. Again, we do not recommend ISDN adapters that require a network card to access our system, they can be configuration nightmares.
Where can I get more information on ISDN adapters?
The best place to start is the newsgroup comp.dcom.isdn, where an ongoing discussion about the merits of different ISDN adapters is available, and where general questions about ISDN are typically answered.
You can call your local phone company and ask to speak to their ISDN representatives to get information on the ISDN service they offer. Don't talk to the normal operators for their standard lines, most phone companies' standard operators typically don't know much about ISDN.
Also, many manufacturers have web sites that describe their ISDN products.
