Are your internal networks a cloud block?

Too many businesses plan cloud services without considering the ability of internal networks to cope with the extra traffic, says Lori MacVittie.

Cloud congestion. It sounds like something you'd hear about on a late night infomercial, but it's a situation that's more and more likely as cloud-based application usage continues to increase among consumers and corporate employees.

While it has traditionally been true that organisations are blessed with more bandwidth than consumers, the advent of broadband has changed that equation. Consumers today are likely to have as much or more bandwidth as corporate entities, even though upstream speeds still lag behind downstream for consumers.

That disparity in connectivity speeds poses a problem for the increasingly vast amounts of data being transferred to cloud-based applications by consumers. Less well discussed, however, is the failure to increase bandwidth at the corporate level before embarking on a large-scale cloud initiative.

Cloud-generated network traffic

When an organisation decides to move some business-critical function, say, CRM or sales force automation, to the cloud, it must also reconsider the ability of its network to withstand the sudden onslaught of traffic.

It's true that web requests and responses are generally not big data and are not as time-sensitive as voice and video, but there will be more of them — many times more — once corporate employees are relying on an external application to perform daily duties.

Lots of little web requests and responses traversing the corporate internet lifeline will have as big an impact on the performance and capacity of that network as the combination of voice, video and email. The more data traverses the WAN, the more congested it becomes, making it more likely to incur performance penalties in the form of jitter and latency.

A US study on internet speeds — 2010 Report on Internet Speeds in All 50 States — suggested that activities involving video, big data, and real-time conferencing require between 10Mbps and 100Mbps upload and download speeds.

That report focused on consumers, but corporate consumers actively engage in these same activities and increasingly rely on cloud-hosted applications to perform business-critical functions.

Some organisations have managed to upgrade to T3 speeds of about 45Mbps in the past decade and remained at that tier of bandwidth due to cost. While fibre rings and other high-speed options have become more available, still the costs associated with corporate internet connectivity have prevented most organisations from breaking past T1 and T2 speeds of 1.5Mbps and 6.3Mbps respectively.

Certainly consumer-grade broadband is more affordable, yet the imbalance of download to upload speed would not provide the boost in bandwidth necessary for organisations to take full advantage of cloud-hosted services.

Network's role in cloud success

The siren call of cloud computing is unavoidable. The lure of running applications without the need to manage their underlying network is indeed attracting more and more organisations. But rather than obviate the need for the network, such services serve to increase dependence on them — and their capacity.

As WAN links become choked with traffic from a variety of business and — admit it — non-business uses, performance suffers. Congestion-avoidance techniques and WAN optimisation can provide only so much relief before it becomes obvious the only answer is to increase the number of lines or upgrade to a fatter, faster pipe.

It is critical to the overall success of any cloud migration project that the capacity of the network be evaluated to ensure it does not become a bottleneck.

It is critical to the overall success of any cloud migration project that the capacity of the network be evaluated to ensure it does not become a bottleneck. Understanding the impact on the business of productivity losses from performance-impaired networks is paramount in building the business case needed to justify the upgrades to the network before launching the migration.

Moving hundreds of staff from using the internal LAN to access applications to using the external WAN will have a dramatic impact on performance and capacity and every other application that makes use of that WAN.

Don't be fooled into ignoring the network when the reality is that migrating to cloud means you're making the network a focal point, the single point on which much of your business will rely.

When you move to a primarily cloud-based model, your internal and external networks become as important to the business as the applications to which they provide access.

Lori MacVittie is responsible for application services education and evangelism at application delivery firm F5 Networks. Her role includes producing technical materials and participating in community-based forums and industry standards organisations. MacVittie has extensive programming experience as an application architect, as well as in network and systems development and administration.