even in the real markets this question is impossible to answer...........
With all due respect Arabian me old chum that's not strictly true (in fact it's total buttocks). FX ecns at institutional level (which I am assuming is what you mean when you say the 'real' market usually have published roundtrip times. And I monitor my own execution speeds to make sure there's no latency in our system over and above what's absolutely necessary. I do this in several ways;
1) By ensuring that I have the appropriate bandwidth available to my traders. This entails liaising with the ecns themselves to discuss optimum pipeline size, type and amount of pricing displayed etc.
2) By ensuring that my trading system itself (i.e. the system that takes the price feeds from the various ecns and aggregates it) is correctly configured.
3) By ensuring that we have the best compromise in terms of price and speed in choice of data carrier.
4) By ensuring that (with the aid of the IT guys) we conduct regular 'ping' tests, to test both the raw speed / latency of our data, and also the actual route it is taking (how many 'hops' and where they are landing) to ensure that we're not doing anything daft. If I'm perfectly honest, this last step is 99% the IT department, and 1% GJ remembering to make sure we do it every so often. Main point I'm trying to make is that the higher end this stuff is very much part of the landscape.
No real benefit to my post over and above a bit of background info I suppose, apart from one thing - I do know that there are bits of software available, afaik as freeware, that will allow other traders, including many here, to trace data routes etc themselves. No idea of names etc, but I am totally sure some here will know what I'm talking about. What benefit one would gain from it when dealing with a retail broker is questionable (as I assume you don't have a myriad options available to you in terms of connection) but if it's of some help then great. If I remember the name of the shareware program I'll post it. There's doubtless more than one, but I think there's one very good shareware program out there that has a good graphical representation of what's going on.
Ok - I'm waffling now - can the T2W members who actually know about this stuff step in now please
GJ