I have Avanti Satellite broadband, the 512 K package, part of the Scottish government roll-out to rural areas. At busy times, response can be terrible. This is clearly because multiple users are sharing the bandwidth. Mostly I can't get anything worth having and just give up. However, as most of their users are business ones, download times are not bad for large single files during the evenings and weekends. Where it really slows down is with complicated web-pages with entries from different domain names on the same page. (Ebay, for instance does this a lot.), this is because of the long latency times; each different domain name has its own latency time. Even in the middle of the night, latency times are absurdly long. I have a 60 second time-out on both email and browser, and about half of all access attempts time out on the first try, but the second try is almost always successful; this points to one specific problem: DNS table access time.
Every ISP has to use a DNS table which converts the domain name part of a URL, (e.g.
www.something.com), into an IP address, (e.g. 49.212.87.198). Generally the server will keep some routing information with the IP address to speed access. This table is really big, (think how many domain names there are on the planet), however most ISPs have a dedicated server, (or several), with lots of memory in it to manage these requests. This way the whole table stays in memory the whole time, and access is almost immediate. In the case of Avanti, either the DNS machine does not have enough memory, or they are using the same machine to do other tasks, and you have to wait for disk access to get to the right entry in the table. The answer is simple: a dedicated DNS machine with enough memory to hold the whole table. This is a relatively simple problem to solve: a little minor investment.
The busy times problem will only get worse, as the Irish and Scottish programmes are rolled out. Solving this problem depends on where the bottleneck is. I am rather afraid that it is in the satellite or its down-link to the earth-station. It may be that extra capacity is available on the satellite, and it is just a matter of Avanti paying for more bandwidth from the satellite owner. More likely, the bandwidth is all used up and Avanti are flying a kite, (i.e. selling something they don't actually have), and hoping that the problems will just go away, or that people will just accept them faute de mieux.
For me, at busy times I am better with dial-up; in the middle of the night, I now have access to streaming videos such as BBC, however I am still badly slowed down with complicated websites that use multiple domain names on the same page of information. Often you get small areas of the page with "unavailable" messages. The only saving is that this package is far cheaper than my phone bill for dial-up was.
John