topics that matter; ideas worth sharing

share a tip, submit a link, add something new

ISDN PRI Pricing

January 24, 2001, 10:53 AM —  Network World — 

Some people may say that ISDN is dead, but that's news to the millions who rely on ISDN Primary Rate Interface service for connecting PBXs and dial-up modem banks to the public network.

While it's true that sales of ISDN Basic Rate Interface service aren't as high as those of competing broadband technologies, PRI sales are going through the roof.

As a PBX platform, PRI's offer more flexibility than traditional analog trunks. PRI's are good for ISPs because they let users connect via 56K bit/sec modems or 128K bit/sec ISDN BRI service.

A PRI offers 23 B channels for voice, video and data traffic via a 1.544M bit/sec T-1 line. The 24th channel, the D channel, is used for signaling. When you combine multiple PRI's, you only need to use one signaling channel for the group of lines, freeing at least one additional B channel for regular traffic. Because of their digital nature, PRI's are equally good at handling voice or data traffic. What's more, PRI will certainly be the access method of choice for connecting voice-over-IP traffic to the public switched telephone network.

Breaking down the costs

The cost of PRI service comprises four components: the T-1 line; the B and D channel arrangements; the trunking arrangements; and special features.

The T-1 charge covers the cost to connect your network to the carrier's switch. In the case of some PRI service providers, you can actually collocate your equipment in the same building with the switch, thus eliminating this charge.

The channel arrangement refers to the way in which you multiplex the B and D channels over a T-1, such as 23B + D, 24B and so on. The trunking element covers services such as Direct Inward Dialing, which lets you give each employee his own direct-dial phone number.

Finally, the special features include options such as calling line ID. When you combine all these elements, you arrive at the true cost of PRI service.

Where to buy

One of the most difficult aspects of buying PRI service is determining if a particular carrier has the service in your area. There's no question that regional Bell operating companies provide the greatest coverage of any PRI provider. Interexchange carriers such as AT&T, WorldCom and Sprint also offer PRI's, but these circuits are typically sold for access to long- distance service.

Competitive local exchange carriers (CLEC) are another source for PRI in larger metropolitan areas of the country -- what some people refer to as the NFL cities. A search on the carrier's Web site or a telecom portal such as www.telcoexchange.com will tell you if the CLEC serves your area, but then you'll need to call the carrier to confirm that it can serve your address. If you have to deploy PRI across the U.S., you should choose a CLEC -- such as Focal, Teligent and Winstar -- that offers national service.

Regardless of what type of carrier you choose, be prepared for extensive installation delays in areas with heavy demand.

I like it!
Post a comment
The content of this field is kept private and will not be shown publicly.
  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.
Resources
White Paper

Symantec Backup Exec 12 and Backup Exec System Recovery 8 deliver industry leading Windows data protection and system recovery. Download this whitepaper to find out the top reasons to upgrade and how to get continuous data protection and complete system recovery.

Webcast

Data and system loss — from a hard drive failure, malicious attack, natural disaster, or simple human error — can happen anytime. Don’t leave your business vulnerable. Make sure you have a secure recovery strategy in place. Symantec's latest backup and system recovery technology can efficiently restore critical applications, individual emails and documents and even restore your entire system in minutes in the event of a loss.

White Paper

Businesses face a growing challenge to ensure that the IT environment is properly protected. Backup Exec 12 integrates with other applications in the Symantec family of products, to complement your current data protection strategy, keep your data securely backed up and make it recoverable when you need it most.

Free stuff
Featured Sponsor

AISO founders envisioned a Web hosting company that was environmentally friendly. While the company employed energy-efficient innovations like solar panels, its infrastructure produced unacceptable power and cooling requirements. Find out how AISO leveraged AMD technology to overcome their challenge in this case study white paper.

In this whitepaper, Scalar explores the opportunity to change the landscape with respect to mission critical databases built around Oracle. Leveraging technologies such as Linux, high-end commodity processing power and Oracle RAC technology to architect, design, build and maintain database infrastructure that delivers maximum availability, reliability and performance at a fraction of traditional cost.

On a typical day, weather.com, the Web site for The Weather Channel in Atlanta, serves up between 15 million and 20 million page views. But in September 2004, when back-to-back hurricanes ransacked Florida, the peak traffic on one day more than tripled: over 70 million page views by more than 7 million unique visitors. Read the full success story now.

More Resources