We are using a business Ethernet connection (3Mbit upload, 3Mbit download) and trying to understand issues with our tested bandwidth speeds. When uploading a large file we sustain 340 KB/s; downloading we sustain 340KB/s. However when we run these transfers simultaneously the two transfer speeds rise and fall erratically with a average speed for both at around 250 KB/s. We’re using a Hatteras HN404 CPi and we’ve bypassed the router (plugged a machine directly into the Hatteras; set the NIC to full-duplex).
Is this expected? Should a max upload interfere with a max download on this type of Internet connection?
It appears that I was wrong about the simultaneous transfer speeds. The 250KB/s speeds up and down were miscalculated by the transfer program (seemed to have been showing a high average speed). Apparently the Business Ethernet (in this case it is an XO circuit provisioned by Speakeasy) only supports 3Mb total, not up AND down (for 6Mbit total). So if I am transferring up and down at the same time in theory I should only have 1.5Mbit up and down or 187.5KB/s at the maximum (if there was zero overhead).