How do I decrease excessive network buffering over Wireless-N
I don't have any specific recommendations when tweaking network configurations. However, I did come across one blog post that discussed various network settings that could be adjusted in /etc/sysctl.conf:


kern.ipc.maxsockbuf=4194304
kern.ipc.somaxconn=512
kern.ipc.maxsockets=2048
kern.ipc.nmbclusters=2048
net.inet.tcp.rfc1323=1
net.inet.tcp.win_scale_factor=3
net.inet.tcp.sockthreshold=16
net.inet.tcp.sendspace=262144
net.inet.tcp.recvspace=262144
net.inet.tcp.mssdflt=1440
net.inet.tcp.msl=15000
net.inet.tcp.always_keepalive=0
net.inet.tcp.delayed_ack=0
net.inet.tcp.slowstart_flightsize=4
net.inet.tcp.blackhole=2
net.inet.udp.blackhole=1
net.inet.icmp.icmplim=50



You'll definitely want to back up the original file before fiddling with these system settings. Various readers also contributed to a lengthy discussion in the comments for the blog post.

Apple Support also has a KB for OS X 10.7 detailing changes that can be made to the MTU for Ethernet, which might also be adjusted for performance issues. However, there were no specific instructions for Wi-Fi.

There's an associated Support KB for older versions of OS X (10.4 and 10.5) that details changes for both Wi-Fi and Ethernet - you may be able to apply use the Wi-Fi instructions in Lion.

If you take the first path (adjusting the sysctl.conf settings), some trial and error may be necessary.