My school pays a fair amount of money for 10Mbps Fibre broadband. So you can imagine how shocked i was to descover that the download speed was 0.19Mbps. (I tested using speedtest.net). This is completely outragous, when an orgainsation pays for good internet and gets a crappy service. I mean 0.19!?… My friend and i have narrowed the possible cause down to this:
My school uses OmniQuad SurfWall remote, which we browse through as a proxy server. We discovered that when accessing the internet using Terminal Server, you could disable using the proxy. We tested this in an ICT lesson, when the internet appeared to have gone down for everyone in the classroom. I went onto TS, and opened IE. Then i tried to access google. No luck. I disabled the proxy and hey presto, the internet works. We believe that the proxy server is not very stable, as there has been a problem with the internet almost every day of the past few weeks.
Using a remote proxy server makes the internet slower, no matter how fast the internet connection the company pays for is. This is because the internet connection is only getting you too the proxy server. Once you get through the server, you are using the Datacenter’s internet. A Datacenter with lots of servers hosting lots of websites is obviously going to have high network traffic. This is the bottleneck of any remote service. Even if you had a 1Gbps internet connection, you won’t be able to utilze that internet connection if the proxy server has a high usage, as i imagine a remote proxy server would.
Therefore, the best way for a company or educational esablishment to use a proxy server is to have one on the local network. You can do this with a physical server, or on a virtual machine using software such as squid. The downside to this is that you have to set it up yourself, or pay someone else to set it up. Then you have to manage it. These all create tasks for ICT network staff which may already be stretched. So a manage remote proxy server has its benifits and downsides. I’ll let you choose 
Disclamer: I am not responsible for anything that may happen if you follow the advice shown on this blog.
EDIT: I have uploaded a screenshot below…
