ISDN Features

Primary Rate Interface (PRI), Answering Calls

How the Telco Handles PRI Trunks

In many cases, the telco will route an incoming PRI call to any of the available 23 circuits on the PRI PCB. This makes it difficult to determine the type of call by the trunk that is ringing. It also prevents using Direct Inward Lines to route incoming calls, since any call sent to the PRI PCB can appear on any circuit. During programming, set up all trunks on the same PRI PCB in the same way. Refer to Programming below.

To provide more precise routing of PRI trunks, set up PRI Direct Inward Dialing (DID). With DID, the sys- tem uses the last three or four digits of the Called Number Information Element to route an incoming call via the system’s DID translation tables. When programming PRI trunks for DID, refer to the Aspire Software Manual (P/N 0893200) for additional DID programming.

In addition, in areas where ISDN is not uniformly implemented, many ISDN calls may route to the 3.1 Khz Audio Ring Group. This can occur if the telco automatically designates a call as 3.1 KHz when it is from a non-ISDN telephone. To provide uniform treatment of incoming PRI calls, consider having the Ring Group assignments for both normal PRI calls and 3.1KHz Audio calls. Refer to Programming below for more information.

How the Telephone System Handles PRI Trunks

The Channel ID of an incoming SETUP message on a PRI line is related to the trunk group number. The system will create the trunk line number as the lowest trunk port number in the range of the same trunk group related to the channel number of the Channel ID information element of an incoming call’s SETUP message.

For example, referring to the chart below, the system translates the call as being trunk port 4.

Trunk Trunk Channel

Number Group Number

111

212

313

424

525

626

727

858

. . . 23 . . . 5 . . . 23

<--- Incoming Call

Conditions

●PRI requires the installation of a T-Serve II CSU (P/N 85950) or Quad Datasmart DSU (P/N 85956). Consult your sales representative for more information.

All 23 circuits on the PRI PCB must be identically programmed since any call sent to the PRI PCB can appear on any circuit.

Default Setting

●Once set, PRI trunks ring extension 301 and flash at all other extensions just like other trunk calls.

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Aspire ISDN PRI Manual

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NEC ISDN-PRI manual Default Setting, How the Telco Handles PRI Trunks, How the Telephone System Handles PRI Trunks
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ISDN-PRI specifications

NEC ISDN-PRI (Integrated Services Digital Network - Primary Rate Interface) is a telecommunication standard that provides high-capacity voice and data transmission over digital networks. Offering exceptional reliability, ISDN-PRI has become a crucial component for businesses seeking robust communication solutions. One of the standout features of NEC ISDN-PRI is its ability to support 23 voice channels, each capable of delivering clear and high-quality audio simultaneously. In addition to voice channels, ISDN-PRI can also handle one data channel, facilitating data transmission at speeds of up to 2.048 Mbps.

A significant characteristic of ISDN-PRI is its digital nature, allowing for efficient use of bandwidth and minimizing issues common in analog systems, such as signal degradation and noise. This technology leverages time-division multiplexing (TDM), which enables multiple voice signals to occupy a single transmission medium without interference. Each channel is allocated a specific time slot, ensuring a seamless communication experience.

NEC ISDN-PRI is also known for its features such as call setup and teardown capabilities. Utilizing the D channel, ISDN-PRI can establish and terminate calls quickly, enhancing overall call management and enabling businesses to handle high volumes of concurrent calls efficiently. Moreover, businesses can benefit from supplementary services, including caller ID, call forwarding, and call waiting, which enhance operational efficiency and customer service.

Security is another critical aspect of NEC ISDN-PRI. The technology includes features like encryption and secure access protocols, ensuring that sensitive data remains protected during transmission. These security measures are vital for businesses dealing with confidential information and seeking to comply with industry regulations.

Furthermore, ISDN-PRI is highly compatible with various telecommunication infrastructures, making it a versatile choice for organizations looking to upgrade or integrate their existing systems. The ability to connect to PBX systems and support multiple protocols adds to its appeal, providing businesses with scalability and flexibility as their communication needs evolve.

In summary, NEC ISDN-PRI stands out as a reliable and efficient communication solution. With its support for multiple voice channels, high data transmission rates, robust security features, and compatibility with various systems, ISDN-PRI is well-suited for modern business environments seeking to enhance their communication capabilities and improve overall operational efficiency.
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