10-15Mbps is quite slow.

you should be able to get at least 10-11 MBps, perhaps a lot more using a Gigabit connection on both computers, which I believe is at least 8 times faster than you report getting

Mbps = Mega Bits Per Second.

MBps = Mega Bytes Per Second.

There are 8 Bits in 1 Byte

Perhaps that's what you meant