KEERAT COMMUNICATION & TECHNOLOGY

252D 2nd floor, Sant Nagar,
East of Kailash, New delhi-65
Tel-No: 011-41326565,9818184113
E-mail : keerat.techonology@airtel.in

ISDN PRI (Primary Rate Interface)

A PRI (Primary Rate Interface) is a telecommunication standard used in the Integrated Services Digital Network or ISDN for carrying multiple DS0 voice and data transmissions between two physical locations. PRI was developed specifically for industrial or large quantity users. The copper line using digital transmission technology, extended from the nearest exchange to your premises is terminated into a Modem (RAD HTU E1 / RAD FCD E1). The PRI circuit is provided using a two pair of copper. It is also known as a 4-wire circuit.

Applications that are widely used on ISDN

• 1. Digital Telephony
• 2. Concurrent use of any two applications like fax, data, voice, video conferencing
• 3. Electronic Data Processing
• 4. Data Transmission on LAN & WAN
• 3. Electronic Data Processing
• 4. Control Internet usage by allocating band width on a pay and use basis.
• 5. Enjoy the benefits of instant access on voice and Net.
• 6. Video Conferencing @ 128 Kbps, 384 Kbps High Quality Video by 3 ISDN Lines
• 7. Internet Access at 64 Kbps or 128 Kbps up to 2Mbps RAS Dialup
• 8.Incoming RAS number.

Proposed 30 Channel digital PRI

• 1. Proposing one ISDN PRI
• 2. 1 PRI= 30 Channels (30 Simultaneous calls)
• 3. 1 PRI would be provided with 100 MSNs [Multiple Subscriber Number]
• 4. MSNs would be provided with DID facility [Direct Inward Dialing]
• 5. ISDN PRI link would be connected to ASM i 52 Modem
• 6. From ASM i 52 with the help of a PRI card it will be connected to the EPABX

ISDN PRI-

Primary Rate Access (PRI):
This provides 30 access channels of 64 Kbps and 1 signaling channel of 64 Kbps (30B + D). This is suitable for corporate connections to ISDN compatible EPABX etc. The 30 digital channels will be used to give 100 direct numbers. 

DID: Direct Inward Dialing

DID is a facility which will give unique numbers to all people in IDP EDUCATION, whereby any person dialing from outside will not need to go through the reception. He shall directly land up on a particular number that he dials.

Benefits of the PRI solution:

Please find below the benefits offered by a PRI line in comparison to an Analog line:

I). PRI line offers digital signaling till the customer's premises as against in the case of analog signal wherein the signal gets digital only at the service provider's premise. I.e. the entire last mile connectivity offers digital signaling through PRI connectivity.

II). Phone tapping in ISDN PRI is not possible at any point neither at the exchange level or the local DP level.

1. The digital signal offers the following benefits:

 a). The call completion is improved as the signaling happens through D-Channel till the PBX.

 b). The sound quality is also improved, as the digital signal is a better quality signal. The noise level is reduced due to the binary signals.

2. The PRI line offers DID (Direct Inward Dialing) facility that carries the following benefits:

a). There is no call waiting for an IVR / when the call is transferred through the operator
b). Everyone gets a direct number at his/her desk.
c). The CLI facility is activated on each extension. Moreover, the desired DID numbers appear on the third party phones when called outside.
d). There is a massive reduction of the traffic on the Epabx.
e). A single PRI line is sufficient for providing up to 100 level DID facility.

 PRI requires the termination of only one physical pair into the PBX that minimizes cross talks and cross-connections over the lines. Moreover, the faults can be traced easily due to this, as there is an alarm at the exchange the moment the line is faulty.