ABOUT THE ISDN AUDIO DIRECTORY FOR PUBLIC RADIO
This Directory attempts to list public radio stations, producers or related facilities that have Switched Digital Audio equipment that utilize ISDN or other studio-to-studio connection methods to send or receive high quality audio. This directory was established to assist public radio producers and technicians in locating sites with which they can do high quality interviews, program transfers or locate remote production sites.
Compatability between codecs has always been problematic. Here's what has been published:
Telos Systems confirmed several years ago that their Zephyr had varying levels of compatibility with other manufacturer's products. Generally, G.722 was compatible across all manufacturer's equipment. With some adjustments, Layer 2 and Layer 3 codecs were compatible between Telos Zephyr, Musicam/CCS and Comrex. View their Guide (PDF)
Tieline has recently published a compatibility guide for their equipment. View their Guide (PDF)
All public radio stations and other related production facilities utilizing "ISDN" or other switchable studio-to-studio connections (SW56, POTS Codecs, IP, etc) are sorted by COUNTRY, then by STATE or PROVINCE.
Numbers assigned to Switched Digital equipment are in the form NNN.NNN.NNNN to differentiate them from the site contact numbers in the same column which are in the format NNN-NNN-NNNN.
The directory lists all known codec compression systems available at each site. They are usually:
While this method of listing codec schemes is only ONE measure of compatibility, it is by far the simplest way. All entries in this directory are with the permission of the sites, and most sites have been tested, however we accept no responsibility for their accuracy.
RELATED WEB SITES
BRIEF HISTORY OF THIS DIRECTORY
This directory was first introduced in 1993 by Allen Rieland who at that time was Director of Engineering at Wisconsin Public Radio (1985 - 2005). He is currently WPR's Director of New Media Technologies. After the installation of WPR's first "Switched 56" terminal in 1992, he found that there was no directory of other "Switched Digital" directory sites available, so he created one with the help of engineers from National Public Radio, Monitor Radio, the CBC and other users of this relatively new technology.
In its original form, this directory consisted of all known "Switched Digital" sites, however the number of commercial users expanded so rapidly that the focus of the list was later narrowed to only Public Radio facilities.
For the first few years, the ISDN Audio Directory for Public Radio was sent to Public Radio Stations via the NPR DACS system every 6 months or so. As the use of the "World Wide Web" increased, a web site became an obvious way to publish a single, updated, on-line directory available for everyone in the Public Radio community.
In September 1996, in an effort to simplify the web-based directory, the 50 separate state and province files were combined into a single web page, still retaining the quick-index feature. The directory is also now easily printable. At the same time, the web address for the directory was also changed and simplified to http://wpr.org/isdn
In 2007, with the demise of ISDN in many locations, this criteria was again loosened to all users, commercial and no-commercial, however the site is primarily for the "Benefit of Public Radio Stations and Producers".
Today as we enter yet another phase in interconnection hardware, we now accept IP Addresses as well as ISDN numbers.
UPDATING THIS DIRECTORY & USER FEEDBACK
You can send in a new entry or update an old one using our On-line Directory Update Form. If you have suggestions, more complex directory updates, browsing problems, or comments, please email them to Allen Rieland at firstname.lastname@example.org, call at 608-263-5544 or write to: Allen Rieland, Wisconsin Public Radio, 821 University Avenue, Madison, WI. USA 53706.
© Copyright 1993 - 2011 by The University of Wisconsin - Extension.