ITAD Subscriber Numbers

ISN provides an easy way for campuses, enterprises, and service providers to acquire globally-unique and globally-routable subscriber numbers to support new communications services. ISNs are free, fast, and forever yours. ISN is also protocol neutral and may be used to support SIP, XMPP, H.323 or other communications.

An ISN is formed by joining a domain-local subscriber number to an ITAD (Internet Telephony Administrative Domain) number, using an asterisk as the delimiter. For example, subscriber 1234 in ITAD 256 would have ISN: 1234*256.

Think of an ISN as an Internet-style phone number, where the asterisk is analogous to the @ sign in an email address.

Getting Started

Participation in the ISN trial is open. The ISN Cookbook can guide you through requesting an ITAD assignment (it's free) and connecting your company or institution to other participating ISN domains.

ISN is still experimental and should not be relied upon for business-critical applications or emergency services.


got ISN?
The ISN Cookbook
A quick tutorial on ISN, including recipes for SER and Asterisk. Contributions of additional recipes (including those for proprietary platforms) are welcome.
Got ISN?
Make one of these nifty "Got ISN?" badges for your web site!
Answers to Frequently Asked Questions.
Mailing Lists
Discuss and announce mailing lists.

The ISN trial is supported by Internet2, Packet Clearing House, and MIT.