You know the adage about a cup being half full or half empty? Maybe the author had software-defined WANs (SD-WANs) in mind. Their ability to select between internet services is critical to delivering stable, predictable performance. But with multiple providers at each site, carrier management becomes a nightmare for SD-WANs. The answer might be Global Managed Internet Providers, also called Managed Network Operators (MNOs) and Virtual Network Operators (VNOs).
Multiple Paths: The key to SD-WAN availability
One of the biggest limitations of any SD-WAN is the dependence on the internet. Over the years, internet performance has improved dramatically. A look at the internet loss metrics from Stanford’s PINGer project show median loss rates across the globe have steadily declined since 1999, improving by 88 percent. Yet for all of its improvement, the internet remains an unmanaged network. Latency and loss rates may outperform private data services on some days, but enterprises look for data services to perform well every day.
SD-WANs try to mitigate performance fluctuations by connecting locations to multiple internet services. Should performance decline across one path, the SD-WAN CPE connecting the location to the WAN can divert traffic to a better performing path. The more paths available, the more likely SD-WAN appliances can find a path that matches the performance characteristics of the given application. Ideally, every office will be multihomed to at least two internet services.
Many providers, many headaches
But adding so many providers to your network creates problems for operations, uptime and more. For one, you now need to find the right provider for each location. Can you really identify the best ISPs in every small hamlet and town where an office might be located?
You also need to be prepared to manage those provider relationships and make sure bills are being paid. Nobody wants to find out that a circuit is down because of a missed bill. And when there’s an outage, who will you call? With so many providers, you’ll need to have the number of more than just a few network operation centers (NOCs) on hand.
+ Also on Network World: IDC: SD-WAN market to hit $6B by 2020 +
Part of the power of MPLS services has been that we’ve had "one throat to choke." Consolidated billing made paying for services much easier. Single point of contact meant resolving problems, in theory, became much easier. If I wanted to roll out a new service or had a question, my service team was the answer. SD-WANs shift that burden back to the enterprise.
Are VNOs the answer?
None of that is to say that you should stick with your MPLS service. SD-WAN and, more broadly, hybrid WANs are the future of WAN architectures. You just need to consider the organizational and operational impact when switching to the technology.
You could find internet providers with broader reach to minimize the problem. Any of the tier-1 carriers, for example, have national networks, but there will always be holes in their coverage, particularly outside of the U.S. Even within the U.S, they might use third parties to service locations outside of their footprint
Many of our clients are looking at VNOs, such as Brodynt, for managing their internet deployments. VNOs take over the management and billing headaches of running multiple providers. You receive one bill from the VNO, and the VNO ensures that all of your ISPs are paid and deliver services as promised. If there’s a problem, you call the VNO NOC, not each individual ISP.
They’re “virtual” because they provide network services without owning the underlying network. VNOs have been particularly popular overseas in the wireless industry because of the high infrastructure cost of delivering a wireless network. More recently VNOs, have started to deliver internet services in the U.S.
SD-WANs are a powerful alternative to MPLS, but organizations need to take care that their agility doesn’t come at the expense of management overhead. VNOs may be an answer. They’ve enormously simplified the life of some of our customers. Do you think ISP management will a challenge for SD-WAN in your organization? We’d like to know. Ping us on Twitter @WANExperts.
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