Thursday, September 15, 2011

What is the difference between ISDN and PSTN?

At the moment I have ISDN and ADSL at home but I am thinking of changing company. They have told me that I will not have ISDN anymore. What does this mean exactly? Will the phone line quality drop? I am completely confused. Anyway, can someone please tell me if there are any drawbacks in my changing the existing situation.
What is the difference between ISDN and PSTN?
ISDN and ADSL cannot co-exist on the same phone line. If you truly have both, you have two phone lines.

If you have two phone lines, you can change one of them to whatever you want (if you can get it - maybe the reason you have ISDN is that you are too far from the exchange to have ADSL).

ADSL is far faster than ISDN - from 10 times to 100 times faster, depending on line quality and distance from the exchange.

ADSL can co-exist with PSTN on the same phone line, so you can make a voice call at the same time as you are online.

To check your situation. go to and check under Exchange Search to find out what's available for you.
What is the difference between ISDN and PSTN?
PSTN (normal phone with normal modem)If you are online, the phone can't be used. You pay per minute. The speed is very slow (56kbps).

ISDN: (digital phone with digital %26quot;modem%26quot;) If you are online, the phone can be used, there are two phone lines. You pay per minute. The speed is slightly better than with a normal modem.
isdn-it is digital , it can carry voice and video on hight bit rate,good for live applications.hight speed networks like 1.5 mbps

types 1.bri-basic rate interface,it has 2b+1d

2 barrier channels for data

1control signal

2.pri-primary rate interface,it has 30b+2d channels

pstn-public network switching telephone network

it is analog,data rate is llow like up to 144kbps,128 kbps ,,dial up networks
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