been watching my speed closely since switch to 21CN a couple of days ago. Have been struggling to understand all the various speeds and am now bewildered. Latest BT test shows: 21 Mbps Max Achievable Speed Download speedachieved during the test was - 11.66 Mbps For your connection, the acceptable range of speeds is 4 Mbps-21 Mbps. IP Profile for your line is - 11.91 Mbps 832 Kbps Max Achievable Speed Upload speed achieved during the test was - 1.16Mbps Additional Information: Upstream Rate IP profile on your line is - 832 Kbps Router says: Bandwidth (Up/Down) [kbps/kbps]: 1,268 / 13,497 Is the router more up to date than BT?
The "bandwidth" stated on the router is actually the line synchronisation speed. A sync speed of 13497 is exactly consistent with an IP profile setting of 11910. and a real achievable download speed of 11660. The router's figure is usually referred to as the line speed or connection rate and is the speed at which the router interfaces with the exchange at. Due to data overheads/checksums and error checking traffic on the line the real download speed you get is always lower under all circumstances. This lowered limit to take account of the 'overheads' is the IP profile speed, however it is rare that people actually do really get the IP profile speed in practice as a download speed - as your result shows.