Other Free Encyclopedias » Online Encyclopedia » Encyclopedia - Featured Articles » Featured Articles: Melissa And Doug Puzzle - What Are Melissa and Doug Puzzles? to Panasonic Mini Dv Camcorders - Panasonic Mini DV Camcorder Great Choice for Pro or Amateur

Monitoring Network Software - Software for Monitoring Computer Networks

traffic type response web

Network monitoring software is defined as that software which monitors a computer network on a constant basis for slow performance and/or failed network components. As a result of the values of the measurement data collected, the software responds in various ways (from a simple displayed graphic, to a transmitted alert, to a restrictive network action, or more) based on rules and criteria previously established. Considered part of the larger field of computer network management, network monitoring software is usually restricted in use to the actual administrators of the computer network. The way in which the network administrator is alerted can take any form already built into the network: email, texting, pre-recorded voice, paging, alarms, or graphics displays.

Network monitoring software can work passively, acting as a transparent bridge through which the network traffic passes and is measured, or can work actively, sending out packets or messages over the network and waiting for a response. An example of the second type would be a monitoring system focused on the availability of web servers — the network monitoring software would send out an HTTP request for a webpage to a specific web server periodically, and measure the response time (or the lack of a response) of the web server. Email systems would be continually tested in the same way.

An example of the passive type would be a network monitoring interface card (NMIC), similar to the network interface card (NIC) found in most computers that is used to connect to a network. Unlike a standard NIC, an NMIC listens passively on a network, does not have a MAC address, and will not announce itself on the network. NMICs are used mostly to create a separate administrative management network, whose traffic is not mixed with the normal network traffic. One reason for such a setup is to ensure the integrity of the administrative management network; another reason is to exclude the traffic used for measuring from normal network traffic.

The most common measures of a computer network are:
- Visibility (is the target visible on the network?)
- Response time (how long does the target take to respond to a request?)
- Availability (how often does the target respond correctly?)
- Uptime (what percentage of time is the target available?)
- Consistency (how consistent/erratic are the above measures?)
- Reliability (what is the pattern of consistency?)

A failure in any of the above measures is indicated by the numerical criteria set up during the install of the network monitoring software. The value of each metric that determines a failure can be set globally, for any subset of the computer network, or by the type of network to be monitored (web, email, application, data storage, etc.). Response to a failure of each type can be as simple as showing a downward tick in a graph on a video display, as moderate as sending text to a network administrator’s pager, or as complex as automatically pulling a server out of a load-balanced array for repair.

Bandwidth management is another aspect of monitoring a computer network — the software will not only measure the amount of traffic, but also the type of traffic, and react accordingly. For example, if the amount of image files being transmitted exceeds a certain threshold, then all image traffic may be restricted on the network.

Network monitoring software will always have some type of graphical administrative console with controls, input boxes, criteria selection areas, and a display of graphs based on real-time traffic. Drill-down will be available for further detail. Network activity will be reported by showing:
- Local IP address
- Remote IP address
- Protocol port number
- Quota for bandwidth
- Alarm indicators

Some of the tools available as network monitoring software are:
- Argus (packet analysis)
- Cacti (polls and graphs of traffic)
- cFosSpeed (classification of traffic, with network shaping and rate-limit capabilities)
- FlowMon (probes and collectors)
- InterMapper (graphical network map showing bandwidth usage)
- NetLimiter (traffic monitoring and shaping)
- OmniPeek (end-to-end network monitoring)
- Observium (auto-discovery, with collection and infrastructure graphing)
- PRTG (graphical and web interfaces, using sniffing or SNMP to monitor bandwidth usage)
- PacketTrap Networks (traffic analyzer)
- Scrutinizer NetFlow / sFlow Analyzer (network traffic behavior)

Monitor Privacy Screen - Why Monitor Privacy Screens? [next] [back] Money To Borrow - Four Places You Can Find Money to Borrow

User Comments

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or