In our last three tutorials, we reviewed the five Specific Management Functional Areas, considered some of the classic systems for enterprise management, and looked at each of seven layers of the Open Systems Interconnection (OSI) Reference Model and used it as a framework for considering the various challenges of managing the enterprise. In those discussions, we found that the lower three layers are typically implemented in hardware, and the upper four layers are typically implemented in software. These distinctions imply that different tools will be required to address implementation or management issues at these various layers, and that the network manager will need more than one tool in his or her toolbox. In this tutorial, we will explore the different categories of tools that would be good to have in your network management arsenal, beginning with those that are used to test the physical layer.
Electronic Hand Tools
At the risk of preaching to the choir, you would not believe the number of clients I have seen over my two decades in the consulting business that did not have some basic hand tools around the office. Avoid frustration, spend a few hundred dollars on a good electronic toolkit, and keep it locked up where you can find it. A good source for these toolkits that has been around for years is Jensen Tools, now a business unit of The Stanley Works.
Environmental Monitoring Systems
These systems alert the network manager to changes in the network physical environment, such as excessive heat or humidity, smoke or fire, commercial power problems, or potential water damage. In many cases, these issues are the responsibility of the plant department, not network management, but if the air conditioner fails in the server room, plan on getting a lot of telephone calls no matter who has the ultimate responsibility. Some of these systems come equipped with wireless sensors that communicate with a base system, and can also alert you via phone, fax or email for event and status updates. Several companies active in this market include AVTEC Software, Sensaphone, and IT Watchdogs.
Just a few years ago, cable scanners to handle unshielded twisted pair cable was the norm, but now with infrared and fiber optic links between buildings, and wireless networks inside, management tools to cover this expanding network infrastructure may need to be updated. So compare the capabilities of your cable test equipment with the various LAN and WAN links that are currently installed, and make sure that you can cover all of the Physical and Data Link technologies that are currently being deployed. Several companies active in this area include Berkeley Varitronics Systems, Frederick Engineering, and Fiber Instrument Sales.
Network and Performance Monitors
In the enterprise arena, the simple notification that a WAN link that is down, or that a server has an unusually high CPU utilization can be key information. Granted, that simple notification may not solve the problem in the long term, but it provides a short term alert that may enable you to re-route the traffic or system to another network and puts you on the path to a longer term solution. Network and performance monitors provide that information. In most cases, they are relying upon either historical data or user-specified inputs to set their operational benchmarks and alert thresholds. In addition, the monitor's output is in the form of color-coded graphs and charts, which can show at a glance if an abnormal condition exists, and also quite useful for upper management's perusal. Monitored parameters may include traffic statistics, call setups/disconnects, failed network access attempts (security breaches), host utilization, server response times, and Quality of Service (QoS) parameters, such as Mean Opinion Score (MOS) results. Examples of companies that are active in this area include: (which recently acquired Brix Networks) EXFO , Codima Technologies, Empirix, Netcordia, NetQoS, and Tekno Telecom.
A protocol is simply a set of rules, and the protocol analyzer determines if the data that was transmitted adheres to the rules that were developed for that system. The advent of the PC changed the protocol analyzer market from the hardware to the software business, and also dramatically improved the capabilities of these devices. Now, multi-protocol, multi-layer functionality is the norm. In addition, many of the devices having embedded expert analysis engines that provide the user with specific details that describe the nature of the problem (e.g. a duplicate IP address), and may also point toward the solution (the hardware (or Ethernet) addresses that identify the offending stations). Examples of companies that are active in this area include: Clearsight Networks, GL Communications, (which recently acquired Network General) Netscout, and RADCOM.
Enterprise Network Management Systems and Remote Probes
In the early 1990s, as network architectures were moving from host-based, centralized systems to distributed routers and servers, the Internet Engineering Task Force (IETF) developed a network framework system and protocol to address this changing environment. That protocol is the Simple Network Management Protocol (SNMP), now in its third generation of release (SNMPv3). An outgrowth of that research is called RMON, which stands for remote monitoring. With RMON systems, a probe is placed at strategic locations within the network, or embedded into those devices, such as routers. The probes then monitor various network parameters and operational characteristics, and report that information back to the network management console. Examples of companies that support SNMP or market remote probes of one kind or another include: Agilent Technologies, RADCOM, Telchemy, and Tektronix.
Network Design and Optimization Tools
The design and optimization of an enterprise-wide, network that includes both voice and data elements is quite difficult - if not impossible - to accomplish using typical analytical tools such as spreadsheets. Over the years, many firms have attempted to develop software solutions for this challenge, and a few have survived. Also in this category are hardware products which can stress test the network, applying simulated loads on the networking components, and then determine how it will perform under those conditions. Examples of companies that are active in the design and optimization area include: Fluke Networks, Ixia, OPNET Technologies, Spirent Communications, and Westbay Engineers.
Our next tutorial will begin an examination of specific vendors' solutions, and see how these products can meet specific enterprise network management challenges.
Copyright Acknowledgement: ©2009 DigiNet Corporation, All Rights Reserved
Mark A. Miller, P.E. is President of DigiNet Corporation, a Denver-based consulting engineering firm. He is the author of many books on networking technologies, including Voice over IP Technologies, and Internet Technologies Handbook, both published by John Wiley & Sons.