There’s a shift in Australia at the moment away from organisations using high-end, expensive MPLS network services from the big providers, towards consumer grade internet services for enterprise WAN connectivity.
It’s certainly not without risk as there’s no application performance guarantee, but organisations can gain at least 400 per cent more bandwidth at a 40 per cent reduction in expenses. This is an attractive offering for many organisations as they face an annual 30 to 50 per cent increase in bandwidth consumption, which is putting a squeeze on WAN budgets.
Currently, the majority of global organisations use the internet in concert with MPLS in a hybrid WAN design for their branch offices, where traffic is “policy balanced” between the two services in an active/active design.
While organisations are already using the internet for very small and remote branch offices, they’re also increasingly using an internet-only approach to support their small to midsize offices. This will likely evolve to include larger offices over the next three years.
Gartner anticipates that 10 per cent of large and midsize enterprises will use the internet as their only WAN service by 2020, up from two per cent in 2017.
Using the public internet as the sole WAN connectivity should only be done, however, by organisations that can accept less predictable application performance than with private MPLS connectivity. Also, those that can allocate sufficient funds, staffing and time to monitor and manage WAN performance and end-user experiences.
The key question is how to manage the variability of WAN performance and, consequently, uneven end-user experience, as sites migrate away from predictable MPLS performance to less predictable or unpredictable internet-only connectivity.
Comparing MPLS to consumer internet
Both MPLS and business internet services are typically delivered as uncontended services, which ultimately means that the bandwidth is fully dedicated to the enterprise, and effective throughput can be 80 to 90 per cent.
Consumer internet, on the other hand, is typically delivered via shared and contented bandwidth, where multiple customers contend for the same uplink bandwidth. This means that effective throughput can be significantly lower than for MPLS and business internet.
However, migration of broadband services to Ethernet over fibre means that ISPs offer 100 Mbps or higher services, at the same price or lower than 10 Mbps xDSL services. Seek the best cost per bandwidth ratio by purchasing consumer internet services of 100 Mbps or more.
Downside to consumer Internet services
Although performance is adequate to good in many cases, consumer internet services are inherently less predictable. There are also no tangible guidelines on how to map them to application performance requirements as with MPLS class-of-service-based application performance mapping.
With growing reliance on internet connectivity, a stronger focus must be placed on how to contain and manage the risk of performance issues than with MPLS.
Many consumer internet services are delivered via asymmetric access services, where download speed is higher than upload speed. For many applications, this won’t pose an issue; however, for high use of videoconferencing or upload of large files, the more limited upload speed may impact performance.
Consumer internet services also often have a certain amount of data that can be downloaded per month and if the allotment is exceeded, the ISP may throttle or block traffic. This may become an issue if large files are frequently downloaded/uploaded.
In many countries, local ISPs will oversubscribe their back-end network infrastructure for financial reasons, in some cases as much as 1:40. This can lead to packet loss and excessive jitter, which in the worst case scenario, can render interactive and chatty applications useless.
In addition, most consumer internet services are delivered without availability guarantees. However, if the service is delivered by a managed services provider as part of a WAN solution, that provider may offer availability guarantees.
Managing the transition to internet-only
To minimise the risk of business interruptions, migrate smaller and less critical offices to internet services first, and migrate larger branch offices progressively as experience is gained. In support of such a strategy, align the performance requirements of critical applications in each branch office against potential internet performance issues.
Using consumer-grade internet will also require security considerations. If each branch office has direct access to the internet, there will be a need to install and manage an internet security solution.
However, it’s also possible to just use internet access services only to establish secure transport connectivity between all enterprise offices, data centres and cloud services, and block all open internet access. This will reduce the need for internet security, and mainly requires a solution that can handle dynamic IP VPN tunnels.
Bjarne Munch is a senior principal analyst at Gartner, based in Brisbane. He advises clients on network services trends, WAN architectures, hybrid WAN, SD-WAN, cloud connectivity and unified communications. He will speak about WAN sourcing trends at the Gartner IT Infrastructure, Operations & Cloud Strategies Conference in Sydney, 29-30 April.