reply almost immediately once the proxy receives it from the origin server. This results 

in any timing information that is logged accurately reflecting the instances that requests 

from and replies to the browser are performing at. 

Any connection problems to the service can be detected and logged. If the proxy is 

located remotely and the host that the browser is running on is disconnected from the 

proxy in some way, any requests to the service, or failures, will not be logged. 

Clearly HTTP proxies and caching proxies in particular, offer significant benefits including a 

saving in bandwidth and reducing latency which result in an improved user experience. A 

HTTP proxies provide the ability to intercept any requests and replies the end user makes to 

a Web delivered service and could be used to indicate the performance as experienced by the 

end user, particularly when placed on the same host that the browser runs on. 

2.6 Summary 

This chapter has covered a number of key issues and areas including the Quality of Service, 

current approaches to Service Management. Service Level Agreements were investigated 

including a briefing on the items that are typically contained in a SLA. Finally an overview 

of technologies that allow monitoring QoS and the description of SLA were covered.