What is ISDN?

ISDN stands for Integrated Services Digital Network and is a method of sending digital transmissions over copper phone lines.

What does ISDN do?

ISDN enables you to transmit data quicker than using traditional analogue transmission methods.

How is ISDN different than a regular phone line?

The difference between using ISDN and regular phone lines can be determined by the waveforms used by analogue modems and digital modems. Analogue lines pick up a lot of Electromagnetic Interference, which makes it more difficult for modems to determine what is being transmitted. In the event that the interference gets too bad, the modems may be incapable of determining what’s being sent and terminate the connection completely. ISDN resolves this problem by sending a different type of waveform which has no degree of variation. Even in the event of interference, it’s easier for the modem to determine how the waveform looks.

Why is ISDN faster?

With the waveform easy to determine, ISDN signals can be sent much faster. ISDN can also use two phone lines simultaneously, with an ISDN line separated into three parts. Two bearer channels carry voice, data, and other services, with each capable of 64kbps. The Delta channel, meanwhile, transmits control and signalling information back to the phone company.

How much faster is ISDN than a regular connection?

ISDN is up to five times faster than regular modems.

What do I need to do to get ISDN?

Contact your telephone company to see whether ISDN is available in your area. If so, your phone company will come to your location and set up the line, usually within two weeks.

What equipment do I need?

Your telephone company will install everything necessary, but you will need specific equipment connected to your computer, such as an ISDN modem or router. To connect multiple computers to a network, you will also need network cards and cable installed

What’s the difference between a modem and a router?

A modem connects directly to one computer, which then connects to the internet. This device may share its connection to the internet with other computers, but will require proxy server software to do so. ISDN modems function just like a regular modem, only faster. A router acts much like an ISDN modem but with the ability to share the internet connection among multiple computers.

What will the ISDN line cost from the phone company?

Costs depend on you location and phone line provider. Contact us today for a competitive quotation.

Can I send faxes over ISDN?

You can send faxes by fax machine or fax modem connected to your ISDN equipment. Plug the fax machine or fax modem into a POTS jack on the ISDN equipment.

Can I make regular phone calls over ISDN?

By connecting your phone to a POTS jack on the ISDN equipment, making calls over ISDN is simple.

What is POTS?

POTS stands for Plain Old Telephone Service, and is what you plug your phone into in the wall. Most ISDN modems or routers have two POTS jacks on the rear for you to connect devices to.

How many computers can connect to a router at the same time?

There is usually no limit to the number of computers you can connect. There are practical limits on how many people you would want downloading simultaneously, since the bandwidth will decrease as the number of users increase.

What operating systems does ISDN support?

An ISDN line is not computer or operating system specific, so you can use any operating system that supports TCP/IP.

If multiple computers are connected, do they each get an IP address?

No. Most routers use NAT (Network Address Translation), which works by translating packets from the LAN address to a WAN address. This means that a router has two sides: a WAN side, and a LAN side. Each side has its own address, with the internet side’s address assigned when the router connects. The router’s local address is assigned when installed. When the router receives a packet from one of the workstations, it remembers which machine the packet came from, translates the local IP address to the WAN IP address, and then transmits.

What’s the best way to assign IP addresses on my local network?

Most routers support DHCP (Dynamic Host Configuration Protocol), which automatically assigns computers an IP address when booting up. When you set up DHCP, you’ll specify a range of IP address to use for the client pool, and only those addresses will be automatically assigned.


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