How flexible, lower cost SD-WAN connectivity makes more sense for the branch office than MPLS

There was a time when the router was an irreplaceable component in the connectivity chain linking the branch office to the Internet – and it was unthinkable that it could ever disappear.

That single piece of hardware has been the mainstay of the wide area network (WAN) for almost thirty years after the first multiprotocol device was built at Stanford University in the 1980s, but its time could finally be up.

That doesn’t mean the routing process can be eliminated – the need to forward data packets between two destinations across different networks and the public Internet is unlikely to go away any time soon. But the dedicated branch office device which has traditionally handled that function is changing into something quite different.

Manageability and scalability considerations

Conventional routers based on multi-protocol label switching (MPLS) technology have a number of issues which should cause IT departments to consider an alternative approach. Firstly, they are expensive – costing anything up to £10,000 depending on the exact specification. And another 15-20% of that purchase price will probably be spent on support and maintenance during its life cycle, more if network engineers need to perform on-site visits to perform upgrades or rectify faults.

Secondly those routers are cumbersome to manage, with configuration generally performed on a manual box-by-box basis using unfriendly command line or basic web interfaces to make changes. All of that takes time for network engineers whose skills could be better allocated to other tasks.

Scalability too is limited to the underlying physical hardware platform, meaning there is always a “compromise of capex” – either pay through the nose for capacity with headroom to expand as the organisation grows, or provision just for today with the risk that you quickly run out of juice and have to fork out for another expensive upgrade sooner than you first thought.

And while you think that a solid, dependable bit of on-premise hardware might be a resilient solution, downtime is a bigger issue than you might think. The device has to be taken offline to perform routine upgrades and maintenance for example, and is susceptible for power failures and even malware attacks. These issues affect pretty much every computing device you can think off, but routers can be more difficult to bring back online quickly and even a few minutes disruption can disconnect an entire office or building from the Internet.

Cost savings on the cards

So if you could get rid of the branch office router for good, what would you install in its place? Fortunately there is now a credible and cost effective alternative in the form of the SD-WAN, which provides the necessary routing and offers IT departments more freedom to use the connectivity of their choice – DSL, fibre Ethernet, WiFi or even 4G for example, alongside MPLS options if needed.

Depending on the manufacturer and existing on-premise infrastructure resources the initial cost of deploying an SD-WAN appliance or server in the branch office could end up being likely to be similar to that of an MPLS router. But there is significant potential to save money on the connectivity SD-WAN enables, whilst the underlying network virtualisation technology also provides scope for network service providers to deliver better value via new on-demand, cloud hosted pay as you go leasing models which may also involve connectivity deals.

Research firm Gartner has suggested that replacing a dedicated, proprietary router with an SD-WAN equivalent can shave up to 40% off the total cost of ownership, whilst even the most conservative estimates point to 10% reductions.

Looking at this in more detail, a single MPLS link can cost anything from £100 per month for 100Mbit/s broadband to over £1,000 per month for a 1Gbit/s UK and International Ethernet for example, with contract lengths typically between three and five years. That compares to some fibre broadband links offering anything up to 350Mbit/s for less than £50 per month (Virgin Media Business), and less than £100 a month for a 1Gbit/s Ethernet link (not including one off connection fees) on a 1 to 5 year contract with BT Openreach.

OK, so availability of those cost effective bandwidth options depends on network coverage and reach of individual carriers and broadband suppliers, most of which are busy extending fibre to the premise (FTTP) deployments into the UK’s major cities, bolstered by strong backing from a government keen to boost Britain’s digital economy. But whatever the pace of that expansion, the advantage of SD-WAN is that companies have more scope to pick the best option available according to their budget and requirements.

Speed of service provisioning a bigger draw

Of course cost savings are not always the primary driver behind every SD-WAN deployment. A recent survey conducted by ZK Research and Tech Target on behalf of Silver Peak found that the need to increase WAN agility and shorten provisioning time to be more important considerations.

Gartner again estimates that IT departments can provision WAN connectivity at new sites up to 80% faster using SD-WAN than dedicated MPLS routers. That’s an important consideration for companies in vertical sectors like retail and hospitality that need to bring new sites online quickly to handle rapid expansion or meet seasonal demand requirements.

Cloud usage demands more efficient routing

Those companies are also far more likely to be leasing software as a service (SaaS) applications and infrastructure as a service (IaaS) resources hosted by third party cloud service providers than they are on-premise infrastructure and software. That might not seem important until you think about how that changes traditional WAN traffic patterns, with more data transmitted between the branch office and remote data centres.

The performance of cloud-hosted applications is also susceptible to latency and jitter, which traditional routers can exacerbate by forwarding data over longer paths and additional hops. Security too is a big imperative, leaving IT managers with the choice of capturing and interrogating suspicious traffic in the branch office itself or putting more pressure on available WAN bandwidth by forwarding it back to their service provider for analysis.

SD-WAN might not have all the answers to these problems depending on localised router configurations, but it is a lot more flexible in the options it provides to solving them.


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.