A Practical Navigator for the Internet Economy

ENUM Protocol Seen As Directory Lookup Tying Internet Telephony Services to PSTN

All Numbers In PSTN Can Be ENUM Provisioned To Identify What Services Their Owner Uses

ENUM Enables VoIP Services To Find Ordinary PSTN End Points - Is Seen As Driver of Convergence

pp. 1- 10, 16

ENUM is the new IETF protocol designed to function like a directory services feature linking PSTN phone numbers to Internet telephony oriented services. We interview Rich Shockey who was co-chair of the ENUM working group.

E164 refers to the international telephone number protocol established by the International Telecommunication Union. E164 resolution means the use of the ENUM protocol (RFC2916) to connect any number in the globally switched telephone network to whatever Internet services have been provisioned for it. Such services may range from a personal web page look up to the ability to retrieve voice mail from anywhere in the world with a local phone call. ENUM makes it possible for the first time to connect a voice over IP service to any POTS phone whose number has been ENUM provisioned.

Currently one SIP provisioned phone can find another only if the owners of each number are aware of the other's existence. Before the web to FTP a file from a directory you had to know it existed or you had to browse directories and stumble by chance on anything interesting. The web became a means of finding and indexing such files and eventually of stitching them together so they could be intelligently located with great ease. ENUM will offer a way for a VOIP service like SIP to transparently find every PSTN phone on the globe whose owner has ENUM provisioned it through national registries to be set up late next year, When a PSTN phone is ENUM provisioned much of its use will begin to flow over the Internet. If ENUM services become as popular as expected, they will be a means by which huge amounts of PSTN traffic will be sucked out of the PSTN and onto the Internet. ENUM has sometimes been referred to as the service control point for the deconstruction of the PSTN by the Internet.

ENUM in a single sentence has been defined as "telephone number in URL out using NAPTR". An ENUM specific domain (in other words the ENUM expression of a telephone number under a single unique administrative DNS domain) must list any and all services available for that domain. The new ENUM GTLD is e164.arpa. It was added to the Root late last month.

ENUM itself is a simple protocol taking only five pages to describe. Shockey reports that the central development issue revolved around a debate of whether or not to use NAPTR records for service discovery. "NAPTR stands for the Naming Authority Pointer Resource record. It is RFC 2915 written by Mike Meeling of Network Solutions and Ron Daniel of Data Fusion. Debate about what resource records had to be returned for ENUM service resolution was extremely contentious."

Shockey describes RFC 2915 as "a profoundly elegant and powerful document for service resolution within a domain. For example it has an ability to list "n" number of services for a domain through the use of regular expressions and a variety of other features and functions. The importance of the use of NAPTR records in this environment cannot be stressed highly enough." Shockey states that the advantage in the use of NAPTR was having a single resolution methodology for resources associated with a telephone number. "If we did not use NAPTR for a resolution we would have issued a sort of directive to the Internet community saying that it was OK to resolve a telephone number to any resource record." (Tony Rutkowski in a short article of his own in Communications Week International also lauds the importance of NAPTR as the glueballs holding ENUM together.)

It seems to the Editor that the intent of use of NAPTR for resource records may be to ensure that the customer has in effect only a single key chain for use in tying together all advanced services to which he subscribes in what is regarded as the most important enabling technology of convergence between telephony and computers as represented by the Internet.

Shockey acknowledges that since ENUM becomes a single point of control and also a single point of failure, the way in which services are provisioned will be absolutely critical. The consumer must be given absolute and total control over his ENUM services which may become the single tool set by which he controls his business and personal communications.

Under this ENUM business model there will be only a single ENUM provisioning authority for each nation state. The IETF and ITU have agreed not to break the e164 mould which means that each national telephone numbering authority will be asked to decide who will provision ENUM services within its borders.

In the US it is likely that an early decision of the new administration will be to choose whether the Department of Commerce or the FCC will issue a solicitation for a national ENUM administrator. Some think that giving the task to the FCC would be both Bell head friendly and ensure a slower role out than an assignment to the Net head friendly Department of Commerce. In any case it is assumed that a successful bidder will have to provide assurances that customer control over the selection of ENUM services and over the privacy issues involved in having what may become a single identifier for all one's telecommunications activity will have to be very carefully respected. It will also be critical to guarantee that when a business or individual changes phone numbers, that all ENUM services attached to an old number are severed from that number immediately on customer disconnect and attached to the new phone number as soon as it becomes live. Critical issues with ENUM are thought to be far more political in nature than technical.

Instant Messaging Coordination of People and Devices Becomes Standards Track High Priority

Serves As An Enabler For Many New Applications, New Uses Of Bandwidth And Intelligent User Agents

pp. 11-16

We interview Henning Schulzrinne, member of the Internet Architecture Board and Director of the Columbia University Internet Real Time Laboratory. Our subject is a tutorial on Instant Messaging and its applications, and on recent high priority IETF instant messaging protocol standardization efforts.

While the ability to send short messages that appear in real time on the screen of the recipient was a feature of most computer bulletin board software, it was AOL's adaptation of this capability that put it one the map of the Internet. From a consumer services perspective it likely ranks behind the Web and email as the third major reason by which people justify their Internet usage. Standardization matters because you now have a problem that there are isolated communities where people who use the Yahoo instant messaging client cannot send messages to people who use either the Microsoft or the AOL client. AOL is appears to have 90 percent of instant messaging users while the remaining 10% are split between Microsoft, Yahoo, ICQ and Tribal Voice.

While this lack of standardization is not now especially daunting in the U.S., it will also begin to get much more important once more advanced wireless services come into play. The popularity of the Short Messaging Service (SMS) in Europe on the GSM mobile phone is huge. Moreover this popularity exists despite the fact that you have to type in your message with the number keys. On completion these messages are sent instantaneously to another mobile phone with bridges to email also available. We can expect that this popularity will migrate with GSM devices to the United States.

Schulzrinne explains that "Instant Messaging is primarily a first order mechanism. In other words you use it to set off other events. This explains where the interest of those of us on the multimedia side came in. What you can do is set up a number of simultaneous AOL, or whatever type, of presence sessions or messaging sessions. When your group is present, you can start up a completely unrelated application such as a voice-over IP conference call."

He also explains how standardization efforts were ramped up earlier this year in the IETF with the decision in the spring in Adelaide to "set up a design competition where the first working group and others were or challenged essentially to put up or shut up." The result was seven or eight submissions that were winnowed into three groups: the XPP or blocks-based proposal of Marshall Rose and Dave Crocker and then "the SIP based proposal which a number of us including Christian Huitema worked on. Within this one, the primary work had started much earlier with a proposal within the SIP working group which Jonathan Rosenberg and I had been working on for some time. Finally there was a whole set of proposals which was called "group two", and which was characterized by a more limited single set of functions for text-based presence indication and instant messaging."

The Schulzrinne Huitema SIP based approach came from a notion of seeing messaging in the more generic sense of event notification. "We see a signaling system consisting of a push part and a pull part if you like. The push part comes in where you call me on the phone to find out if I'm available. The phone rings and either I pick up or I don't. The pull apart would be when I tell you, just in case you wanted to know, whether I'm available to talk or not. These two are mirror images of each other and thus it makes sense for them to be provided within a similar overall signaling framework that includes the ability to reach end systems."

He explains the power of using SIP not for a just an "I call you up mode" but also for an "I notify you when I'm available mode," and an "I want to find out when you are available in order to subscribe to" mode means that all of these messages are handled by the same set of software or so-called proxy servers. "You can think of those as being cousins of your SMTP server. If as we expect, the next generation wireless systems will all use SIP internally, we will have an infrastructure with a billion users on it. We might as well leverage this infrastructure since the proxies do not have to be upgraded in all in order to have this functionality."

"Consequently a proxy does not even have to be aware that instant messaging or presence is going on. Therefore a proxy built today will be a perfectly capable router of subscriptions and notifications regardless of what happens to its details in the future. To us, this capability opens up an avenue for integration which hopefully will lead to lots of interesting new services." Among these will be SIP based notification or execution of events. An instant message may turn on a remote white board or web cam while it may also notify someone of a remote event such as change in the condition of an on going process.

Commerce Department Formation Of ICANN Seen As Illegal End Run Around The Administrative Procedures Act And The United States Constitution

Michael Froomkin's Findings To Be Published In Duke Law Journal

Lawrence Lessig Lauds Froomkin's Creation Of Framework That Could Force Reform

pp. 17 - 21

We summarize and comment on Michael Froomkin's 166 page 711 footnote long landmark paper: "Wrong Turn in Cyperspace: Using ICANN to Route Around the APA and the Constitution" to be published by the Duke University Law Journal, October 2000, Volume 50, No. 1. Froomkin's indictment in his opening paragraph is succinct: "The United States government is managing a critical portion of the Internet's infrastructure in violation of the Administrative Procedures Act (APA) and the Constitution. For almost two years the Internet Corporation for Assigned Names and Numbers (ICANN) has been making domain name policy under contract with the Department of Commerce (DoC). ICANN is formally a private non-profit California corporation created, in response to a summoning by U.S. government officials, to take regulatory actions that the Department of Commerce was unable or unwilling to take directly. If the U.S. government is laundering its policy making through ICANN, it violates the APA; if ICANN is in fact independent, then the federal government's decision to have ICANN manage a public resource of such importance, and to allow - indeed, require - it to enforce regulatory conditions on users of that resource, violates the non-delegation doctrine of the U.S. Constitution. In either case, the relationship violates basic norms of due process and public policy designed to ensure that federal power is exercised responsibly."

We believe that it is very important to use Froomkin's compelling insights to educate both citizens and the executive and legislative branches of the US government. We need to understand quickly what has happened and why we should "be afraid." Out of such education it is to be hoped that legal or legislative redress may be found. In a brief interview with us Larry Lessig explains that Froomkin has provided a road map for legal that under the right circumstances could be used to compel ICANN to change its ways. The almost final draft of the Froomkin paper is a 1.1 meg pdf file at http://www.law.miami.edu/~froomkin/articles/icann1.pdf We also offer comments on the recently concluded ICANN membership at large elections.

Some Insights On Network Service Level Agreements

pp. 22-23

We publish a NANOG discussion on issues to consider in evaluating quality of service agreement with upstream providers.