ENUM is an IETF standard (RFC 2916) for mapping the public telephone number address space into the Domain Name System (DNS). It specifies how to use DNS to locate services associated with ITU’s E.164 addresses, in other words with normal phone numbers.

The Redwood City, California-based ISV has been talking about ENUM for the last few years, initially using its standard carrier DNS server, ANS, for ENUM functionality, recalled George Smine, its senior director of product marketing. In March 2006 we launched our first dedicated product for ENUM, our Navitas IP application routing directory, he went on.

That release of the product was for networks running end-to-end, however, while the new release, version 3.0, is designed to work in mixed environments where there is a lot of legacy TDM equipment. For this reason, Smine went on, Nominum has added support for SIP, the emerging standard for signalling in IP telephony.

The logic here, he went on, is that most legacy network equipment can talk some SIP, so this enables it to talk to our ENUM data repository without the need for an upgrade to talk native ENUM. This lowers the barrier for entry to ENUM for application servers and switches and makes Navitas switch-agnostic.

The new Navitas module that brings SIP support is called the Application Routing Module, whose name indicates where Nominum sees the carrier market going. In other words, the whole Web 2.0 paradigm of data services accessed on carrier networks will require a lot more data management as servers, as well as people, need to be contacted, so the company positions Navitas as a network or service control point.

For this reason too Nominum is introducing another component called an Element Management Solution or EMS, serving as a single console from which multiple instances of Navitas can be managed centrally. Navitas replicates in a massively distributed, master-and-slave architecture, so this enables the carrier to maintain consistency across all those servers, said Smine. It also means an individual instance can be taken down for maintenance with EMS controlling which others can take over while this is going on.

Our View

While the new features Nominum is adding into Navitas clearly grow its value proposition, they also speak to the fact that ENUM uptake has been painfully slow and limited. There is a consensus that ENUM is a desirable thing, but most carriers don’t want to commit the funds to deploying it today, with all the capex that it would entail.

Where the ISV is going with this move is to enable such time-honored carrier activities as least cost routing for the world of IP telephony, which in turn should enable its potential customers to see more short-term gains, not to mention a more gradualist capex strategy for implementing it.