Is "High" what is recommended on your room settings screen? I believe mine is recommended at "Standard" but I probably have a slower connection.
Also, in the in-game manual, section 9-3, you can read what GT5 says about the room settings if you would like.
Ok, there was a lot of information in there and depending on how much we trust a GT5 manual (cough)matchmaking(cough) all our questions are answered in there.
First of all, it does say that the having mics on can cause some issues but you can limit those issues either by disabling them or turning the "voice quality" down. Mine was on "standard" so I've turned it down 1 notch to "low", there is one more option of "very low" before totally disabling them.
Second, the "race quality" determines the frequency with which GT5 sends/retrieves data with the network. A higher frequency requires more demand on the resources and thus has higher chances for errors. GT5 automatically determines each users optimal setting and anything higher than that could cause issues. My recomended setting was "standard" but it was on "high" so I have moved it back down.
Next, there are 2 ways to setup the connection of a room, Fixed Host and Non-Fixed Host. With Fixed Host selected it uses what's called a Star Network where everybody connects directly to me but not with each other. If there are compatbility/connection issues it will only be between the host and the player and not between players so the room is slightly more stable.
With Non-Fixed Host it uses what's called a Mesh Network where everybody shares a a connection and sends data between everyone in the room. This has a higher chance for errors between players but apparently reduces lag and inconsistincies during races.
My Lounge has been set to Non-Fixed status which is supposed to provide smoother racing so that suggests to me that the majority of our problems Tuesday were due to network congestion, but obviously I had a few settings that could be optimized. I did a connection test, I'm Type 2, 15.0 Mbps download/2.3Mbps upload, bandwidth "very high".
Based on this information it looks like the biggest thing we could do would be change to a Fixed Host status, the downside of this being that once I leave the room it will "cease to exist" (exact words from the manual). I know sometimes people hang around afterwards so somebody would have to open another room if you wanted to continue. As dsgerbc said, we don't want to change anything too drastic in the middle of a points week so I think we should just try the lowered race and voice quality at first and next week we will try doing it with a Fixed Host status. North America will be getting our DLC on this Tuesday so we should see a similar surge in network activity which will be a good test.
Thoughts?
*EDIT: I shut down my laptop and iPad and my connection improved to 18down/3.5 up