PSTN vs PSDN vs ISDN | Difference between PSTN,PSDN,ISDN
This page compares PSTN vs PSDN vs ISDN and mentions difference between PSTN, PSDN and ISDN networks. PSTN stands for Public Switched Telephone Network, PSDN stands for Public Switched Data Network and ISDN stands for Integrated Services Digital Network.
PSTN-Public Switched Telephone Network
PSTN stands for Public Switched Telephone Network. It consists of access network and core network. The connection between telephone and exchange is known as access network. The connection between exchanges is known as core network.
The modem is needed to connect computer for data communication as modem converts digital data to analog form in order to transmit on analog lines. The receiver side modem converts analog data to digital data.
Following are the features of PSTN:
• It uses circuit switching.
• Bandwidth is reserved in advance.
• Dedicated path is established between calling party and called party.
• cost is based on distance and call duration or time.
Refer Telephone System tutorial➤ EPABX basics➤
PSDN-Public Switched Data Network
Following are the features of PSDN:
• It is designed and developed specifically for data transmission rather than voice.
• Communication is shared i.e. many companies share switching network.
• It uses packet switching.
• It acquires and releases bandwidth as needed.
• No dedicated path exists between sender and receiver.
• Cost is not based on distance and time. It depends on usage of the data. Cost of service is normally lower than leased line.
Examples: X.25 Frame Relay ATM
ISDN-Integrated Services Digital Network
ISDN stands for Integrated Services Digital Network. It is designed for transmission of voice, data and video over digital line.
There are two forms used in ISDN viz. BRI (Basic Rate Interface) and PRI (Primary Rate Interface).
• BRI provides two number of 64 Kbps channel and single 16 kbps control channel. Total data rate supported by BRI is 144 Kbps.
• PRI provides 23 number of 64 kbps channel and single 64 kbps control channel. Total data rate supported by PRI is 1.544 Mbps.
Refer ISDN BRI vs PRI➤ ISDN 2B1Q signal format➤ ISDN tutorial➤