If we compare the progress of disk sizes over the last decade from megabytes to terabytes, it would follow that in order to move that data quickly between machines we need terabit connections. Unfortunately, progress essentially stopped with the gigabit ethernet connection until recently when we saw the 10 gigabit ethernet connection hit the market. Overall, however, the amount of 10 gigabit networks in place today versus gigabit networks is tiny. Systems architects and engineers have known about this issue for a long time, but the Cloud has pushed the issue to the forefront as it stresses the current capacities of networks around the world.
Cisco has just released its Global Cloud Index for 2010 to 2015 and it estimates that global cloud computing traffic will grow by a factor of 12, from 130 exabytes to 1.6 zettabytes annually by 2015. Keep in mind that 1 zettabyte is 1 trillion (that's right - with a T) gigabytes. That is a massive amount of data that will be moving across connections that are predominantly 1 gigabit or slower. According to the report, the Cloud currently occupies 11 percent of datacenter traffic but will triple to occupy 33 percent of that traffic by 2015.
Also, by 2015, the composition and direction of datacenter traffic will shift to where 76 percent of that traffic will remain within the datacenter, 17 percent of the traffic will leave the datacenter toward and end-user and 7 percent of the traffic will go between datacenters for things like storage replication, multi-site application communication, off-site backups and Cloud bursting (federation). By 2014, Cisco estimates that over half (51%) of the datacenter workload will be within the Cloud infrastructure versus the traditional infrastructure. This is huge for private and public Cloud vendors as they must prepare to handle this massive shift of workloads to their Cloud infrastructures.
"Cloud and data center traffic is exploding, driven by user demand to access volumes of content on the devices of their choice. The result: greater data center virtualization and relevance of the network for cloud applications and the need to make sense of a dynamically evolving situation,” said Suraj Shetty, vice president of product and solutions marketing for Cisco. “The Cisco Global Cloud Index provides insight into this traffic growth and trends so that organizations can make strategic long-term decisions. We will continue to develop and release the Cisco Global Cloud Index on a regular and ongoing annual basis, contributing to ‘cloud readiness' efforts worldwide."
As a Cloud Architect, all I have to say is that Cisco, or another networking vendor better bring the terabit connectivity, and fast! When you add the total amount of Cloud traffic that will need to flow between datacenters to the growing amount of data being replicated between SANs, you quickly realize that even 10 gigabit networks are inadequate for where we are headed. Its time networking caught up to disk, processor and memory density, and that means terabit networks.