[e2e] packet size distribution of Internet traffic

[Nicolas Christin]

On Tue, 15 Apr 2003, [gb2312] Jing Shen wrote:

> Hi, I'm reading some paper on router arch., and found someone
>announced that average packet size is about 1000b. But some other
>persons said the packet size distributes in a large spetrum and most of
>them are of 64byte or 1024byte. I want to know is there any paper on
>this? thanks in advance.

Jing,

The "typical" packet distribution is tri-modal, with the modes at or
around 40 bytes, 560 bytes, and 1500 bytes. A useful reference is "The
nature of the beast: recent traffic measurements from an Internet
backbone", by Claffy, Miller and Thompson, presented at INET 98. It is a
bit old, but I believe the packet distribution (see Figure 3) is still
pretty accurate.

Please also note that, for ease of internal scheduling, routers
generally internally deal with fixed size cells(*), i.e., they split up
incoming packets into fixed size chunks at the input before reassembling
them at the output. These chunks are however much smaller than 1000
Bytes generally (around 100 bytes, but it varies depending on the
specific model of router you are looking at).

(*) term abusively borrowed from the ATM world, but this also holds for
IP routers.

Best regards,
-- 
Nicolas Christin
University of Virginia, Computer Science
http://www.cs.virginia.edu/~nicolas