Windows 7/ v6.2.3
Bell Fiber, 1Gb/s D, 120Mb/s U connection
more info available upon request.

When hosting or joining others servers.
Sometimes when I use voice chat, there will be up to a ~30 second delay before they hear what I say and another ~30 second delay before I can hear the response.
The only port I have forwarded is 7777 Both, which I use for hosting.
I do notice that the auto NAT punch through tend to fail when some people join.
I suspect it might be the router, but its a brand new router.

It is not an immediate issue for me, as it doesn't happen all the time.