XML Marks the Spot

Posted: 02/2000

XML Marks the Spot
By Charlotte Wolter

Every once in a while, a simple idea has so much power it changes an entire industry.

Many XML (Extensible Markup Language) users believe this straightforward technology is
such an idea. XML is an uncomplicated but versatile way to identify data in web pages so
they can be extracted and used in any application.

XML is burdened, however, with second coming-type hype, especially among computing
industry users. Its real potential is evident in that it already has become a force in
several industries–information technology, telecommunications and electronic commerce.

"People make absurd claims about XML, saying it will make a revolution because it
is so powerful," says Chris Harris-Jones, senior consultant with research firm Ovum
Ltd. (www.ovum.com). "While it may make a
revolution in some ways, such as freeing up electronic commerce because everyone can
exchange orders or documents, the main reason it is so powerful is that it is so
simple."

What is XML?

At its simplest, XML is a markup language, like HTML, of which it is a superset. It is
used to create web pages where the content is text and data. "Tags" or coding
are inserted before and after text for web pages, using the forms ""
and "" to identify text as data.

In web pages, HTML coding, which uses the same format as XML, specifies how text will
look. It is designed to make it easier to read.

XML makes it possible for a machine to read and use data on a web page. The
"tags" specify what data they are, such as last names or account numbers.

This marked-up file of text data can be sent across a network. Data created for one
application also can be marked up and used by another application.

"A piece of XML generated by a Microsoft Corp. (www.microsoft.com)
application can be read by an Oracle application," says Harris-Jones. "It’s
completely universal."

Simplicity is only one of XML’s virtues. "We believe it has taken off because it
was produced by the World Wide Web Consortium (W3C), so there are no alliances with any
one vendor," says Harris-Jones.

Each industry creates its own set of tags, sometimes called schema. An information
technology (IT) industry group is creating tags so data can be passed along in the supply
chain for all companies that build computers.

"They are identifying a common vocabulary that can be used within that industry,
and a lot of companies are contributing to each stage," says Harris-Jones.

XML acts as a go-between that provides a level of abstraction. In other words, it is a
universal way of expressing data, which can be read by different kinds of applications.

The data entered on an XML web page are not used directly, but are translated into
forms that applications, and network hardware elements, can use.

XML pages are different from a traditional database of information. First, the data are
created as web pages, which means that data creation can be opened to many users,
including customers.

Using an XML-based web page, a telecommunications services customer could make changes
to account information or order new services. The customer is not changing the database
directly, which could be dangerous for any service provider to allow. Rather, a web page
is changed, and then it is used to create databases.

The only blemish in the XML picture is that the vocabularies are far from universal. In
some industries, notably electronic commerce, several different tag schema are under
development.

"Unless everyone speaks the same XML language, it is all the more complicated
because you have to communicate between XML vocabularies," Harris-Jones says.

XML Intelligent Networks

As communication network elements move toward becoming software running on standard
computing platforms, a datacentric technology, such as XML, gains power. Next-generation
networks rely on databases and servers to provide their intelligence, and XML provides a
way to create intelligent network (IN) services.

DTI Networks Inc. (www.dtinetworks.com), a
developer of switches and IN services running on standard computing platforms, has created
its own tag system for telecommunications networks. It is called Call Processing Markup
Language (CPML). DTI has submitted CPML to the Softswitch Consortium for consideration as
a standard.

CEO and chief technology officer for DTI Richard Graves says, "Because XML
provides data that is self-describing and machine-readable, it is the technology to
drive the transition from the circuit-switched world to future cell- and packet-switched
networks."

Graves says packet-switched networks need a language, such as the CPML, to describe
voice services. "Now you have voice services that are self-describing and machine
readable. So you can create new features that my TDM (time division multiplexing) switch
can read, interpret and activate, but they were created using human-readable
technology."

A standard XML creation tool can be used to create services. ALEC Inc. (www.alec.net), a CLEC based in Paducah, Ky., has DTI’s XML
system for a wide range of services.

For example, if a customer has multiple phone numbers at one location, ALEC creates a
call route for each number. With XML, the call route can be done once, and stored (on a
Netscape server in the case of DTI). Then the tool can copy the XML text specifying the
original route to create the others.

"We don’t have to code XML," says Jay Campbell, president, ALEC, which uses a
Netscape tool and directory server. "There are lots of off-the-shelf tools that work
with an XML server. XML is a superset of HTML, so it allows us to take a browser and deal
with the XML in a graphical intuitive fashion. We can show the links from data to call
routing records that are similar, and can find them and show them on the screen."

DTI employees currently use the XML tools that DTI supplies, but ALEC could create its
own web pages and interfaces for employees to enter data, Campbell says.

This way of defining services is consistent with the new vision of distributed networks
that have much of their intelligence at the edge.

Besides being used to create and update the databases that specify services, XML can be
used to control switches and other devices that actually deliver services. In the same way
Java uses virtual machines to communicate with different computing platforms, XML uses
"switching objects" that represent feature sets a carrier or switch maker
defines. These are translated for each switch. It also can support major protocols, such
as session initiation protocol (SIP) and media gateway control protocol (MGCP).

The result is that call processing and feature creation are decoupled from the
switching fabric.

"Everyone is fearful of stranded investments in [features for] TDM," says
Campbell. "But when the network does transition–because call processing is where the
real value is, the features, the customer databases and interfaces to processes–we can
salvage the core of the investment."

The additional layer of XML abstraction is a safety and ease-of-use feature, Campbell
says. "The hardware does the switching and … the hardware talks only to the XML
server. When my people provision services, I don’t want them to mess with the hardware.
And I want their interface to the whole thing to be as simple as possible."

Broadsoft Inc. (www.broadsoft.com), a provider
of service creation and delivery platforms for packet- and circuit-switched telephony,
uses XML in its BroadWorks service-creation system.

"We see XML as a good way of accessing databases on the customer-provisioning
side," says Broadsoft spokesperson Scott Wharton. "In the near term we think it
will be used on the provisioning side."

Long term, Broadsoft agrees XML will be a significant factor in controlling services,
Wharton says.

XML Everywhere

DTI is one of several next-generation-network firms adapting XML for telecom service
creation and delivery. Cisco Systems Inc. (www.cisco.com),
for example, has announced XML-based Cisco-Works 2000, a web-based management family that
will enable service providers to monitor the quality of their services over VPNs.

Merlot Communications Inc. (www.merlotcom.com),
a maker of integrated access devices (IADs) for small and medium-sized businesses, has
XML-enabled its Magnum Applications and Services Platform. The Magnum functions as an
intelligent edge device that interfaces to the WAN and is involved in service
provisioning.

Working with Broadsoft’s software, a service provider or third party can create
enhanced services applications and deploy them on the Magnum at the customer premise
rather than throughout their infrastructure.

Micromuse Inc. (www.micromuse.com), a provider
of fault and service-level management software, uses XML in its Netcool Internet service
monitoring product, which is used by web-hosting services. Netcool’s various monitoring
tools store data in XML format, which enables that data to be integrated into other
software, such as Microsoft’s Excel.

Trouble Looms?

A cloud hovers above XML’s horizon that could create significant future difficulties.
Each industry is creating its own XML tags, and different systems of tags are emerging
within the same industry.

Sometimes a group of companies forms a specialized group of XML tags. Some companies
are struggling to bridge two different tag systems in the firms with which they must deal.

If that were not enough, some companies are adding bits to the basic XML codes to get
better-defined specifications. Microsoft has produced a system called XML Data that is an
enhancement to XML.

The W3C is addressing the issue, but as a consortium it often cannot move as quickly as
the market does to develop new XML variants. The situation is likely to continue until the
W3C produces its solution, XML Schema, Harris-Jones says. This will allow XML to specify
characteristics of data, such as the number of decimal places. This would be important if
a piece of data is a bank balance, because the system would know to reject it if it did
not have two decimal places, or if the data included a letter.

Charlotte Wolter is infrastructure editor for PHONE+ magazine.