I know you guys have gone through a lot of settings trying to resolve this issue. I also noted that you are using Padavan's custom firmware.
In the router settings/advanced settings/firewall Click Netfilterand have you tried the different options under NAT type? Full Cone, restricted and classical linux/hybrid nat?
I would think that Full Cone might resolve the issue. Good luck.
I don´t think so - because if I put my xbox in the DMZ I also co host connections.
If you read here (you need powerpoint viewer) Solution No4 you will see it.
http://www.microsoft.com/en-us/downl...s.aspx?id=7288
If I understand Solution 4 right then:
let me explain:
A strict NAT and a moderate NAT can´t connect to each other.
But they can both connect to an open NAT.
think we have 4 players
1. player open NAT choosen as host
2. player open NAT not host
3. player moderate nat
4. player strict nat.
connections:
1. player connect to all and all connect to him
2. player connect to all and all connect to him
3. player connect to player 1 and 2 but NOT 4
4. player connect to player 1 and 2 but not 3
the connection between player 3 and 4 has to be bridged. xbox live chooses an open nat with enough bandwith for example player 2.
If player 3 shoots on player 4 for example the packets can´t go direct to player 4 (remember they can´t connect to each other) it takes the route over player 2. So the latency for player 2 increases because he co host the session for player 3 against player 4.
If your game session have many open NAT´s and only some moderate NAT´s there is no problem - but if there are some strict NAT´s ALL connections between them and between all moderate NAT´s needs an open NAT who run their session. This increase latency for the open NAT owner.
If you disable all Port Forward and DMZ and also UPnP then you get a moderate NAT. You can´t co host Sessions, because you can´t connect to all the strict NAT´s. You the get only "normal" lag (because of distance because of ping and so on) but you get no lag because of co hosting too many sessions.
I´m not a specialist in Networking and many things I don´t know. But with a moderate NAT ALL games on xbox live run much better for me. Read the microsoft powerpoint and you see that it works like I wrote or similar
For me all the lag started with better Internetconnection. My Bandwith was much higher than before and my ping times is much lower. So I think if you have enough available Bandwith xbox live matchmaking will choose you as host.
So if you read that people limit their upstream and it helps then - it´s not because of game mechanics it´s because the bandwith is too low to co host I think (this is NOT in the powerpoint from microsoft)