Application Inefficiency and the Total System Effect

The applications utilizing a given transport mechanism are responsible for effectively and efficiently dealing with the environment that they are implemented in. Often however, applications are introduced into environments for which they are not designed and are not well equipped to handle. Transactional systems like database applications, Point of Sale, and real-time response are noted for poor performance in degraded networks. Additionally any applications which rely on “chatty” behavior (highly acknowledge packets), or multiple transactions can also be adversely impacted by degraded network conditions. Additionally, the above types of applications are also impacted in a highly significant manner by effects of latency and fragmentation in the network transport medium. In the image below (utilizing the same test application, now configured to conduct database transactions, and transport medium as in the Latgency and Fragmentation examples) shows the effects on a transactional system of latency and fragmentation. Of a rated 5Mb/s capacity the performance dropped from ~557kb/s with zero errors to ~63kb/s with a remarkable 44.2% error rate, the actual “goodput” on this connection was less than 30kb/s. Relatively long interruptions displayed are the result of the application either locking or halting as retransmissions and fragmented packets act as a packet flood, in effect creating a localized and self inflicted denial of service.