New Communication Technology Poised for Commercial Launch before End of 2005

Following a trial phase lasting several years, ENUM ought to be ready for the transition to a regular operation around the end of 2005. That is part of the plans presented by DENIC at the fifth ENUM Day on 28 September. ENUM is a new technology that builds a bridge between telephony and the Internet. For users, ENUM and the services associated with it, open up the whole world of communication through their standard telephone numbers. Just one number is then enough to be reached via a fixed-network or mobile telephone as well as by fax or even by e-mail or webpages. ENUM is also used for linking different voice-over-IP networks.

The German domain registry, DENIC, has been running a trial with ENUM domains since September 2002 with the involvement of numerous providers and other interested companies and institutions. The overall appraisal at the end of all this testing is, on balance, a positive one. During the presentation of the final report on the field test during the ENUM Day, Andreas Bäß, a member of DENIC's executive board stated: "now is the right point in time for a successful market launch of ENUM; the market is waiting for ENUM". He added that there is now a very general consensus amongst all those involved that the ENUM product has arrived at commercial maturity. One of the main things that customers wishing to use ENUM will notice with the move into commercial operation is that, in future, they will have an increasingly wide choice of new product solutions from ever more suppliers. Currently, more than sixty DENIC members are already able to handle requests dealing with ENUM domains, and more than 3600 such domains have already been registered in Germany. This figure is deceptively low, since one ENUM domain is sufficient for operating whole telephone installations with unlimited numbers of extensions, which means that the number of subscribers already using ENUM is very much higher. One good example is the Saarland University in Saarbrücken, which is already using ENUM for all its extensions.

The fifth ENUM Day was also an excellent opportunity for participants to receive the latest information about a whole series of other matters. Richard Shockey, who coordinates the ENUM working party at the international standardization body, IETF, presented the current state of standardization endeavours and the plans for further developments in future. Dr. Martin Fröhlich gave a report on the challenges regarding numbering and routing that are facing suppliers of voice-over-IP services. As a bridge between the worlds of telephony and the Internet, ENUM also has the capability of providing potential solutions here too. Michael Volpert presented a gateway built around an ENUM lookup, which makes it possible to reach IP subscribers from PSTN too.

Background to ENUM

The term “ENUM” is derived from “telephone number mapping”. It is a protocol defining how to link together resources from the telecommunications and Internet spheres. It sets out a rule by means of which a telephone number can be uniquely mapped to a domain. This domain can then be used for the identification of various communication services, such as telefaxes, cell phones, voice-mail systems, e-mail addresses, IP-telephony addresses, web pages or call diverts.

The idea behind ENUM is simple yet ingenious. Instead of having to grapple with lots of different numbers and addresses for private, office and mobile phones as well as telefax, e-mail and websites, which demand a really big effort just to keep them up-to-date, it is going to be possible in future to enter just one single number per person in our address books. Making sure that each communication is routed to the appropriate output device is then going to be handled by the entries in the ENUM name server.

The linking of telephone numbers and Internet resources is leading to the creation of totally new services. One basic service is finding an Internet terminal with telephony capability from a conventional telephone. As an option, it is possible with ENUM to draw callers’ attention to alternative communication channels that are actually available. If no Internet device with telephony capability is available, the caller will be able to select an appropriate alternative from the list of additional applications presented.

ENUM is also frequently used to establish connections between voice-over-IP terminal devices residing in different provider networks. This avoids the situation where telephone calls across network borders would have to revert to the conventional telephone network, which would cancel out the cost benefit of Internet telephony.