It's not the router that causes lag. Any wireless standard (a/b/g/n) has a maximum speed much faster than the DSi's 2Mbps. Your internet connection will probably be 2Mbps or faster, so that's not the problem either.
We can conclude that it is one of two issues: network latency or server overload. If you are transferring a lot of data in your home network, the router will queue up requests, and the chat data will come through later.
It much more likely that the server takes longer. Imagine 100 or so people accessing your home PC every 10 seconds. That's a good idea of what happens to the server, so that is the reason.
We've known each other for so long.
Your hearts been aching but you're too shy to say it.
Inside we both know whats been going on.
We know the game and we're gonna play it.
And, if you ask me how I'm feeling,
Don't tell me you're too blind to see.
(Ooh)Never gonna give, never gonna give(Give you up)
(Ooh)Never gonna give, never gonna give(Give you up)
We're no strangers to love.
You know the rules and so do I.
A full commitments what I'm thinking of.
You wouldn't get this from any other guy.
I just want to tell you how I'm feeling,
Gotta make you - understand!
Never gonna give you up,
Never gonna let you down,
Never gonna run around and desert you.
Never gonna make you cry,
Never gonna make say goodbye,
Never gonna tell a lie and hurt you.