Originally Posted by jasonmerc
What this does is sets your PC's network packets to have a Time To Live of 65. This is to make it seem like the packets were originated from your phone instead of your PC. Android's default TTL for its packets is 64, so when the PC sends packets to your phone through tethering with a TTL of 65, they have a TTL of 64 by the time your phone sends them out to T-Mobile's towers (the internet).
Thanks, jasonmerc! This put me in the right direction to remove the need for PdaNet on my Mac and also to be able also use my phone as a Wi-Fi Hotspot at full speed on T-Mobile. I'll be looking for your tutorial to bypass T-Mobile's international speed limits!
For those wondering how to do this on a Mac, it can be done temporarily using:
sudo sysctl -w net.inet.ip.ttl=65
Or permanently by creating or editing /etc/sysctl.conf to add
if you end up creating the file, you will need to be sure and do:
sudo chmod 0644 /etc/sysctl.conf
sudo chown root:wheel /etc/sysctl.conf