“How you invest in networking today is going to impact what you get out of it,” he said in an interview discussing a recent report he co-authored, Getting the Network Ready for Cloud.
Many organizations aren’t planning ahead far enough into the future when preparing for cloud computing, he says. Far from simplifying the network public and private clouds add a new layer of complexity.
“You want to avoid squeezing too many virtual machines down a pipe that has too many switches in the way,” Senf says. “With the right technology you’re going to get more out of the network.”
But administrators have to look at their networks from top to bottom, asking what their needs are for cloud computing. If your organization has branches will you need more wide area network (WAN) optimization? Remember, as the IT stack goes virtual the amount of data travelling along the network increases significantly. Will you need a virtual private network (VPN) not only for security but to improve latency? What kind of a service level agreement do you need from your provider?
The preparation is essential. Senf knows of a large financial services organization building a private cloud environment for delivering virtual desktops to thin client terminals that “ran into pretty significant network challenges.”
The interface between the company’s servers and its storage area network and between the end points and the data centre had to be updated, he said, which hadn’t been anticipated.
The shift to a two-layer network architecture from three layers is only one result of organizations thinking about the implications of cloud computing, the report says.
Fewer switches reduces latency. On the other hand, the report adds, it increases the risk of failure because there’s less redundancy, so the choice of network equipment becomes more important.
The report identifies six network-related areas that organizations should consider to prepare for cloud computing:
–Private cloud, public or mix? The type will have a major impact on network requirements, says the report. Think about your organization’s security, quality of service (QoS) and peak network needs;
–Set some QoS and SLA goals. There is, of course, no SLA for the public Internet. But you do need to find an acceptable baseline for latency, loss and mean time between failures. To reduce trouble, look at your existing potential bottlenecks such as the SAN.
–Ensure you have enough visibility into your current network. Virtual switches help performance, but unless you’re using the latest tools you may have monitoring trouble;
–Security doesn’t shift to the cloud provider. In fact, it means tougher monitoring of virtual machines, data classification and tough corporate security policies;
–Governance doesn’t shift away either. Set key performance indicators to track capacity planning, upgrades, incidence response and use satisfaction across various workloads.
–Finally, be ready for some infighting. Shifting to a private cloud may pit the server administrator against the network administrator. Shifting to a public cloud may pit the business user against IT. There needs to be agreement on who does what.
Without a cloud migration plan, the network will still operate, the report concludes, but operations expenditures will be higher and opportunities will be squandered.
