Network traffic patterns are changing as mobile devices and an increasingly reliance on streaming video shape how data traffic is consumed from the data center.
Two types of traffic are emerging. One, commonly referred to as “mice” traffic, are short-lived data flows that typically last 10 seconds or less and consume relatively little bandwidth. This is the type of traffic where a mobile phone might ping a data center for a nibble of data, for instance.
The other type of traffic, known as “elephant” traffic, typically lasts anywhere from 10 seconds to several minutes and has a much higher bandwidth use. These are the data flows that are pulling video data such as a Netflix stream, for instance.
“Mice flows tend to be bursty and often latency sensitive, whereas elephant flows normally perform transfers of large blocks of data, with packet latency of less concern,” noted a recent application note by Alcatel-Lucent (News - Alert), SDN Analytics for Elephant Flow Marking. “Without intelligent traffic engineering, elephant flows may fill network pipes causing latency and or service disruption for mice flows.”
That’s because the majority of bandwidth is taken up by elephant flows. Data from Sandive shows that 72 percent of peak downstream bandwidth consists of large flows when it comes to fixed access connections, and 55 percent of mobile connections are of the elephant type. If operators are not careful, these elephant flows can run havoc on the network, impinging on the multitude of short-duration, low-bandwidth connections that flow in and around the elephant flows.
The solution is application fluency and a software defined networking (SDN) framework.
“Traditional network architectures are static requiring significant operational resources to keep up with the demands placed on them. And, most don't meet the business needs of controlling costs and improving agility,” noted the Alcatel-Lucent application note. “Enterprises need and are demanding solutions that improve their operational efficiency and business agility.”
Through virtualization, automation and application-aware network logic, SDN can solve the elephant and mouse flow problem by adjusting virtual network resources to accommodate the traffic needs of the moment. If there are more elephant flows than network devices currently are provisioned to service, SDN can automatically adjust resources and launch new instances of virtual network resources to meet the need.
Adjusting to network flows is a prime example of the power of SDN in action—and it is a solution to a problem that every operator is starting to face.
Edited by Peter Bernstein