PSTN vs ISDN: Which Business Landline is Right for You?

PSTN vs ISDN: Which Business Landline is Right for You?

Many businesses just assume that a landline is a landline … until they go to sign up for one. Regular business landlines come in two flavours: PSTN and ISDN. (We’ll leave VoIP to one side for now, and talk about that another day.) Both systems have their pros and cons, and the ideal solution for your business may well be to use a combination of the two.

PSTN (Public Switched Telephone Network)

PSTN, which is also called POTS (Plain Old Telephone System), supplies a single phone line with a single phone number. This service is ideal for smaller businesses that require only one or two lines. It is also recommended for many services where a dedicated line is required, such as fax and EFTPOS machines, back-to-base alarm systems, and ADSL connections.

ISDN (Integrated Services Digital Network)

An ISDN digital service provides multiple channels per line, and enables multiple concurrent phone calls. Each digital line can carry both voice and data services. These lines provide greater bandwidth than PSTN lines, which makes them well suited for services including data transfer and video conferencing.

This service is ideal for medium to large businesses, and is typically connected to office phones through a PBX system. For most businesses, only 30-40% of their phone lines are in use at any one time. That means that in an office with 10 staff where everyone has their own phone, you would require either 10 PSTN lines or 4 ISDN lines. This helps to make ISDN cost effective, especially in larger offices.

With ISDN, each phone within your business can have a unique phone number, which people from outside the business can dial directly. (This is called a DID or Direct In-Dial number.) You can typically purchase DID numbers in blocks of 100 from your telco. When you purchase a block of numbers in this way, they remain yours, and you can take them with you if you ever decide to change to a different carrier.

Which one is right for your business?

ISDN used to be the phone system of choice for medium to large business. However, newer technologies like hosted PBX and unified communications have overtaken its popularity among businesses. Smaller organisations are more likely to rely on a PSTN solution.

Your main consideration should be the future growth of your business. Alltel solutions specialists can help you with getting Business Phone Lines to match your specific needs. Just give us a call on 1300 ALLTEL if you need any help deciding which type of line is best suited for your business.

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