document: Understanding Internet traffic streams : dragonflies and tortoises We present the concept of network traffic streams and the ways they aggregate into flows through Internet links . We describe a method of measuring the size and lifetime of Internet streams , and use this method to characterize traffic distributions at two different sites . We find that although most streams -LRB- about 45 percent of them -RRB- are dragonflies , lasting less than 2 seconds , a significant number of streams have lifetimes of hours to days , and can carry a high proportion -LRB- 50-60 percent -RRB- of the total bytes on a given link . We define tortoises as streams that last longer than 15 minutes . We point out that streams can be classified not only by lifetime -LRB- dragonflies and tortoises -RRB- but also by size -LRB- mice and elephants -RRB- , and note that stream size and lifetime are independent dimensions . We submit that ISPs need to be aware of the distribution of Internet stream sizes , and the impact of the difference in behavior between short and long streams . In particular , any forwarding cache mechanisms in Internet routers must be able to cope with a high volume of short streams . In addition ISPs should realize that long-running streams can contribute a significant fraction of their packet and byte volumes-something they may not have allowed for when using traditional `` flat rate user bandwidth consumption '' approaches to provisioning and engineering
doc_bio_tags: O B I I O B O B O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
extractive_keyphrases: internet traffic streams dragonflies tortoises network traffic streams traffic distributions mice elephants forwarding cache mechanisms internet routers
abstractive_keyphrases: internet stream size measurement internet stream lifetime measurement isp long-running streams packet volume byte volume traffic provisioning traffic engineering