The primary application of ISDN PRI is for connectivity between Customer Premise Equipment, such as Private Branch Exchanges (PBXs), and the Central Office. Benefits to using ISDN PRI over traditional channelized T-1s include greater efficiency, faster call setup and teardown times, dynamic call allocation, configuration flexibility, superior voice quality, and access to advanced features such as Calling Line Identification and Dialed Number Identification Service.

ISDN PRI is designed over a standard T-1. It is most often divided into 23 B-channels and 1 D-channel where the D-channel is used to direct the traffic among the B-channels. By moving the signaling onto a dedicated signaling channel (“out-of-band”) ISDN PRI B channels are able to carry more information than traditional channels in analog T-1s (64 Kbps versus 56 Kbps). ISDN calls, which are digital by nature, also offer faster connection times, faster tear down times, and clearer signals when compared to conventional analog Public Switched Telephone Networks.

Telephone Features

• Traditional Voice Services – ISDN PRI allows for access to the Public Switched Telephone Network and all its standard features including access to Emergency Services and Message Relay Service
• Direct Inward Dialing (DID)
• Reserved DID
• Calling Line Identification (CLID)

Network Features

• Backup D-Channel

Advanced Routing Features

• Call Throttling
• Call-By-Call Routing
• Overflow
• Temporary Local Redirect
• Release Link Trunking (RLT) or Two B-Channel Transfer (TBCT)

Other Features

• Greater capacity, higher efficiency, and broad flexibility all combine to deliver a cost effective solution for our customers!
• PRI has greater efficiency than traditional channelized T-1s. Reducing the overhead associated with in-band signaling results in 23 ISDN PRI B-channels being as efficient as 32 analog lines (assuming normal customer traffic patterns)
• Faster call setup and teardown
• The flexibility to configure individual channels within a single PRI as bi-directional, unidirectional, or any combination
• Superior voice quality to traditional analog voice quality
• Advanced features, such as Calling Line Identification and Calling Name Identification, can provide the necessary personal touch required for call centres to elevate their service to the next level