Well do to the lack of hundreds upon hundreds of threads like this, I will have to guess that there is something on your side. Possibly a firewall?
See if the problem was with BW then everyone would have this issue. So never rely on other games MS being low and that the problem cannot be on your end due to that.
Check the router/modem and reboot, check the firewall to allow SWTOR to access easily, as well check with your isp to make sure there is nothing on their end vs yours. I know that some Isp's had difficulty with wow itself and some type of setting, until the ISP worked with BW to get it resolved.