tag:blogger.com,1999:blog-16621283459648044812011-11-27T15:42:19.352-08:00federicohttp://www.blogger.com/profile/02440122708772023677noreply@blogger.comBlogger11100tag:blogger.com,1999:blog-1662128345964804481.post-12461542902358339702007-12-29T18:04:00.000-08:002007-12-29T18:05:21.517-08:00The term network monitoring describes the use of a system that constantly monitors a computer network for slow or failing<br />systems and that notifies the network administrator in case of outages via email, pager or other alarms. It is a subset of<br />the functions involved in network management.<br />While an intrusion detection system monitors a network for threats from the outside, a network monitoring system monitors the<br />network for problems due to overloaded and/or crashed servers, network connections or other devices.<br />For example, to determine the status of a webserver, monitoring software may periodically send an HTTP request to fetch a<br />page; for email servers, a test message might be sent through SMTP and retrieved by IMAP or POP3.<br />Commonly measured metrics are response time and availability (or uptime), although both consistency and reliability metrics<br />are starting to gain popularity. The widespread addition of wan optimization devices is having an adverse effect on most<br />network monitoring tools -- especially when it comes to measuring accurate end to end response time because they limit round<br />trip visibility.<br />Status request failures, such as when a connection cannot be established, it times-out, or the document or message cannot be<br />retrieved, usually produce an action from the monitoring system. These actions vary: an alarm may be sent out to the resident<br />(SMS, email,...) sysadmin, automatic failover systems may be activated to remove the troubled server from duty until it can<br />be repaired, etcetera.<br />Monitoring the performance of a network uplink is also known as network traffic measurement, and more software is listed<br />there.<br />Website monitoring services usually have a number of servers around the globe - in America, Europe, Asia, Australia and other<br />locations. By having multiple servers in different geographic locations, a monitoring service can determine if a Web server<br />is available across different Networks worldwide. The more locations used, the better the picture on your website<br />availability.<div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/1662128345964804481-1246154290235833970?l=triple-network-monitor.blogspot.com' alt='' /></div>federicohttp://www.blogger.com/profile/02440122708772023677noreply@blogger.com0