kBps aka KBps is a different measurement than kbps aka Kbps.
A small "b" indicates a measure of bits. A large "B" indicates a measure of bytes. There are 8 bits within a byte.
For example:
4320KBps = approximately 34,000 Kbps, aka 34 Mbps.
4320Kbps = approximately 500 KBps, aka 0.5 MBps
If it is a measure of bytes(B), 4320 KBps and 2390 KBps are very fast speeds. If it is a measure of bits(b), 4320Kbps and 2390Kbps are still faster than average speeds, but 8-times slower than their KB counter-parts.
An overwhelming majority of speed test websites and ISPs choose to measure speed in Kbps so that it sounds faster. For this reason, I strongly believe your speed is in the measure of kilo-bits-per-second.
On the other hand, download managers and p2p applications usually measure speeds in KBps.
As an example for my network...
Speedtest.net measures my download speed as 3.30 Mbps (3300 Kbps).
The maximum download speed I can achieve via Vuze (torrent downloader) is approximately 400 kBps (aka 400KBps).