STANDARDS-BASED MANAGEMENT FOR CONVERGED NETWORKS
BY BROUGH TURNER
Historically, administration and management of telecom equipment was proprietary. Each
PBX had its own approach: the Bell System built a large set of standards, but only for
their internal use. The past twenty years have seen the breakup of the Bell System and an
explosion in the telecom equipment business. But, except for the emergence of an ITU
standard called TMN (Telecommunications Management Networks), management of telecom
equipment and telecom networks has remained a highly specialized field with mostly
In data communications the story is dramatically better. Here a single protocol, SNMP
(Simple Network Management Protocol), has emerged as the standard for managing anything
that is part of the Internet. And, with the telecom market waking up to the Internet, SNMP
is making inroads into the telecom equipment industry. Other Internet standards- notably
one called RADIUS- handle authentication, for example when you log onto an ISP. Meanwhile,
MIS directors need to manage zillions of PCs is driving a new class of management
In fact, enterprise management is driving developments far beyond SNMP and RADIUS. The
field of enterprise management includes desktop PCs, LAN equipment, WAN access equipment,
connections, services and service policies (grades of service), plus servers, and someday
soon corporate telecommunications. And the direction for managing this all-encompassing
network is being determined by developments in the world of computers - PCs - moreso than
by developments in the Internet world or the IETF.
CURRENT NETWORK MANAGEMENT
Most equipment in the Internet, as well as the equipment in the core of most enterprise
networks, is managed using SNMP. Each managed device contains one or more MIBs (management
information bases) that define device-related information, plus SNMP agents, that is,
software that can take information from an MIB and publish it over the network. These
components allow central management software to interrogate each device and retrieve
Unfortunately, SNMP v.1 the current standard has inadequate security. As
a result, SNMP is used only to report statistics such as how many packets a router has
dropped, what the current routes are, what the traffic levels are, or whether its T1
trunks are in red alarm mode. Re-configuration via SNMP would not be safe. It may not be
desirable for hackers to discover how much traffic a router is handling, but it is
completely unacceptable if they can break into the router and change its configuration or
turn off specific ports. So, configuration changes are typically accomplished by other
means, like a Telnet session with a proprietary command line interface. While management
system software may make this transparent to the network administrator, the interface is
specific to each device and proprietary with each vendor.
Efforts to enhance SNMP have been underway for years. SNMP v.2 was completed several
years ago but, due to continuing security issues, was not widely adopted. Recently, an
IETF working group completed SNMP v.3 as a set of draft standards. This version addresses
security issues, and the Internet community is hopeful that it will provide a way to not
only monitor network devices, but also administer and configure them.
AN UNEXPECTED FORCE
But an interesting initiative from the PC world may actually supercede SNMP v.3, at least
in the enterprise, before v.3 is widely deployed. WBEM (Web-Based Enterprise Management)
is emerging as a likely solution to the problem of managing PCs in an enterprise and, in
fact, managing the converged enterprise network. Until now, MIS directors have had a
limited set of tools for administering their PC infrastructure. Indeed, in most cases, it
is still necessary to send support personnel to individual offices to maintain equipment.
But big changes are finally at hand.
Some years ago, Microsoft got serious about PC administration and management, perhaps
in response to requests from MIS directors, or perhaps more specifically in response to
the threat of the Network Computer. In any event, in 1996 Microsoft
contributed a large body of work to what is now the Distributed Management Task Force
(DMTF) and, jointly with Cisco, Compaq, Intel, and BMC software, announced an initiative
called Web-Based Enterprise Management. In 1998, the WBEM initiative was also transferred
to the DMTF.
The first thing that the WBEM/ DMTF initiative did was to define an object-oriented
information model a way to describe any kind of manageable entity. This is called
the Common Information Model (CIM). CIM fills the same function as MIBs in an SNMP system,
but CIM is a significant improvement over MIBs.
The MIB hierarchy is flat and has only had to support SNMP, which in turn has been
limited to manager-to-agent polling and simple data sampling. CIM is extensible and can
structure large amounts of complex data. And CIM is object-oriented. This makes it faster
and easier to build management solutions by normalizing diverse devices through a concept
called inheritance. A core schema defines general characteristics of any
manageable entity information that will be inherited by all devices. Then a set of
common schemas define information models for the concepts and functionality
needed for manageable entities in five broad areas the system, device, application,
network and physical schema. Finally, extension schemas model specific
platforms, protocols, or corporate brands.
Perhaps CIMs most important feature is its ability to show the relationships
between different components in an enterprise network. Using CIM, You can see this
computer is associated with this application, that is running services that are out on
this server, says Winston Bumpus, DMTF president and Novells corporate
WBEM goes on to define transport mechanisms and interfaces to support information
sharing between software products. As the name implies, WBEM can support browser access to
data, but other interfaces support integration with most existing system and network
management technologies. Not surprisingly for a technology that originated with Microsoft,
WBEM takes the embrace and extend approach. WBEM can completely wrap existing
SNMP-based equipment, and WBEM systems can export information to SNMP management systems.
It is clear that Microsoft is the most visible force behind WBEM. In fact, even as I
write this, if you go to the DMTF web site and look at
the WBEM tutorial, its in Microsoft Help File format. This means it can only be read
with Internet Explorer, and not with Netscape Navigator not very friendly for an
impartial industry consortium! On the other hand, CIM is elegant, and WBEM is eminently
suitable to the tasks of enterprise management.
WBEM has endorsement and active support not just from Microsoft, but also from Cisco,
Intel, and Compaq and the major vendors of management applications like HP and IBM/Tivoli.
And, there is major Unix support expected, which will probably be public by the time you
read this. So we are certain to see a wide variety of devices supporting WBEM/CIM.
Its unlikely WBEM will overwhelm SNMP in the near term you will see SNMP
support in routers and switches for years to come but it is equally clear that WBEM
is the way PCs will be administered in the enterprise. With WBEM support in Windows 98 and
the latest versions of Windows NT 4 (since Service Pack 4) and CIM support in a variety of
other contexts, expect widespread WBEM deployments over the next two years.
The next evolution in management capabilities will be directory-enabled networks (DENs).
Here again, the DMTF is the focus of the action. Increasingly, MIS directors and ISPs have
been looking at enterprise directories such at Novells Netware Directory Services or
Netscapes Directory Server as a way to get control of the information needed to
administer users, addresses, and access rights across a network. The problem is that
modern corporations can have dozens or even hundreds of separate directories and user
databases with separate IDs and passwords for separate purposes.
The DEN initiative was a response from Microsoft and Cisco that promised to leverage
Microsofts forthcoming Active Directory to solve the same problem. Of course, Active
Directory was vaporware while Novell and Netscape had products. Luckily, this initiative
was also turned over to the DMTF, and Novell and a wide range of additional companies are
participating. The DEN initiative uses the same CIM information model that is fundamental
Once widely deployed, mostly likely within 23 years, DENs will support a new
class of networked applications where users can access identical services no matter where
they are: at home, at the office, or on the road. However, the promise of DEN is not just
information sharing among diverse directories, but also more automated management of
devices. If a user can connect to a network at any location and have their desktop appear
as they last left it, then we can also envision plugging in a replacement piece of
equipment, identifying it once, and having the rest of its installation and configuration
BEYOND DEVICE MANAGEMENT
Management issues, however, go beyond administering routers and switches in the network or
PCs on the desktop. With the converged network, another kind of management is required:
The need for policy management can best be illustrated through an example. ATM networks
can provide quality of service (QoS) guarantees, an invaluable capability for enabling
high-quality voice and video services, but it has created a need to allocate and
administer the higher quality services. Who gets to use them and with what priority? Is an
individual user allowed to tie up 2 Mbps of bandwidth for a video conference every Friday
morning, or only 384 Kbps?
These are policy questions. And with the advent of QoS initiatives for IP,
such as RSVP and DiffServ, the IETF is also faced with policy management issues. These are
being addressed in the IETFs Policy Framework working group set up last year. Their
goal is to provide a framework that can represent, manage, and share policies and
policy information in a vendor-independent, interoperable, and scalable manner.
Interestingly, this IETF working group is using CIM as their information model! So the
WBEM initiative is already beginning to have an impact on the Internet.
A CHANGING MANAGEMENT LANDSCAPE
Network management and enterprise facilities management are both entering a period of
great change. Standards-based management systems are expanding from routers and switches
to the desktop. And object-oriented technology developed for the desktop PC is coming back
to add to and improve the Internet. As we move to a converged network, this will greatly
benefit telecommunications. At a minimum, your corporate telephone directory should be a
seamless part of the rest of your MIS infrastructure. In time, we should see the same open
systems benefits that are driving progress in enterprise management systems begin to
affect even the mostly proprietary world of corporate telecommunications.
Brough Turner is senior vice president of technology at Natural MicroSystems, a
leading provider of hardware and software technologies for developers of high-value
telecommunications solutions. For more information, call Natural MicroSystems at
508-620-9300, or visit the companys Web site at www.nmss.com.
E-mail to the author is also welcome.