Kbps in networking

m4rtin

"1 kbps" means 1000 bits per one second. "1 Kibps" means 1024 bits per one second. What does "1 Kbps" mean? In addition, with larger SI decimal prefixes and IEC binary prefixes there seems to be no such confusion. I mean prefix indicating the magnitude is always the capital letter. For example Mbps(10⁶), Gbps(10⁹), Tbps(10¹²), Mibps(2²⁰), Gibps(2²⁰) or Tibps(2⁴⁰).

NetworkVeteran

Rfc 1594:

rfc 1594 wrote:

Kb kilobit
10^3 bits of information (usually used to express a
data transfer rate; as in, 1 kilobit/second = 1Kbps = 1Kb).

ptilsen

I have never seen anyone actually use binary prefixes to reference bits. No Kibps or Mibps or anything like that. They are simply not needed. KiB/S or MiB/S would be acceptable for byte transfer rates, although unnecessary as throughput denominations in units of Bytes/second are implied to be as binary-prefixed units of bytes, not decimal (SI prefix) units of bytes. No one will ever say KB/s and mean 1000 bytes a second, nor will anyone ever say Kbps or kbps and mean 1024 bits per second.

The only capitalization differences are between bytes and bits. KB/s is kilobytes/second, while kbps is kilobits per second. Kbps is also bits, and I see no significance between whether the K is capitalized. KBps I would interpret as kilobytes, but again, it's completely non-standard to use anything other than the forms bps or Bps (bits per second) or B/S (Bytes/second).

To recap, bits are realistically never expressed using binary prefixes -- they are always decimal. A kilobit is always 1000 bits, and no one is going to think its a kibibit. Bytes are only referred to ambiguously in terms of storage media -- disc and disk vendors refer to units by SI prefixes rather than binary, which is why you'll occasionally see terms like kibibyte (KiB) used when the amount might be ambiguous. In transfer rates and file systems, byte units use binary prefixes. Networking throughputs are measured in decimal bits, and if converted are converted to binary-prefixed measurements of bytes/second, never decimal bytes/second.

I'm no CCNP, so I invite the networking guys to correct me if I'm wrong. I've just never seen binary prefixes used for denominations of bits per second in anything, ever. They have no value as additional units in networking as I understand it, nor any value in software/programming/file systems.

f0rgiv3n

I agree with you ptilsen, and yet I keep it simple for myself...
kbps, Kbps = kilobits
KBps,KB/s = kilobytes

IMHO it's just the capital on the b that makes the difference. b = bit B = byte . If anyone writes anything else I just look at them weird.

ChooseLife

There's been a lot of confusion over
1024 vs 1000, kbyte vs kbit, and the capitalization for each.
Here, at last, is a single, definitive standard

al3kt.R***

Wikipedia reads:

k- stands for kilo, meaning 1,000, while Ki- stands for kilobinary ("kibi-"), meaning 1,024. The standardized binary prefixes such as Ki- were relatively recently introduced (in IEEE 1541-2002 that was reaffirmed on 27 March 2008 and still face low adoption. K- is often used to mean 1,024, especially in KB, the kilobyte.

Also take a look here for common problems Data rate units - Wikipedia, the free encyclopedia

regards