This article demonstrates the process of debugging performance issues of SSRS reports at the client end. When everything seems okay right from the execution of stored procedures related to the report, to network and report server configuration, one is required to look into what's going over the wire i.e. what's going out and coming in from the client network. This issue is not specific to SSRS reporting. In any web-based server side application development, when the web application is to be debugged for performance issues or even when it needs to be benchmarked for certain parameters, this method is used. And the method is placing an HTTP Proxy or HTTP Sniffer.
This tool can be installed on any of the client machines, and any HTTP activity effective due to report execution on the client machine and network can be logged and investigated. The most promising features of this tool are, firstly its a freeware. This tool comes with several add-ons which are very much suited for analyzing the content and requests that flow over the wire, with all the minute details that can possibly be captured. It's a very nice tool for performance debugging and in my viewpoint, BIDS should have shipped with this kind of tool. This tool is developed using Microsoft .NET and also provides the flexibility to extend the code.
Thumbs up for this tool and the article which itself is a great tutorial explaining the methodology of performance debugging of SSRS reports from a client network.
Reference: Tom Mills Blog