MPLS Network Provider Secrets
As an MPLS Network service provider, we can let you into a few secrets about MPLS's use in the real world.
MPLS is Primarily Used By Network Service Providers, Not By Their End Users
Ordinary firms can use MPLS, but mostly it's used by MPLS network providers themselves.
They like it because it simplifies setting up virtual routes across their core networks, supports traffic prioritisation and allows traffic to be rerouted almost instantly in the event of downtime.
MPLS network providers often run their services over a patchwork of underlying networks provided by different suppliers, as this allows them to extend their coverage cost-effectively. MPLS creates a useful layer of abstraction that makes network management easier for providers and their customers.
When it comes to global MPLS networks, it's practically mandatory for providers to use circuits from different national network providers, as no single provider is likely to have a physical fibre network in all the countries of interest. International fibre networks exist but are mainly designed to connect data centres, not end-user sites. ISPs turn to national carriers to create any links that are required between those data centres and their customers' local locations.
MPLS Typically Ends At The Provider's End Of Leased Lines, Not At The Customer's End
Labels are applied to traffic when they enter an MPLS network and stripped off as the traffic leaves the network by the final router or penultimate router encountered.
Many people who buy MPLS WANs assume that MPLS runs all the way to their site. It may. More likely, it will end at your MPLS network provider's end of the leased line.
This approach is cheaper than having costly MPLS-enabled equipment at each customer site.
Generally, firms only run MPLS all the way to their sites if they need to ensure connection downtime lasts less than a second.
Most Network Connections (Including MPLS Ones) Are Underutilised Much of The Time
MPLS can be used to help prioritise traffic. However, prioritisation is only really needed when there's not enough bandwidth for everything to be transmitted through the preferred routes at once. Prioritisation is a bit like insurance. It's reassuring to know it's there, but it's not actively making a difference most of the time.
Connectivity pricing involves steep volume discounts, with a ten-fold increase in bandwidth merely doubling prices. As a result, infrastructure-level and wholesale-level suppliers tend not to offer a full range of bearer circuit speeds, offering 100Mbit/s, 1Gbit/s, 10 Gbit/s instead. This causes MPLS providers to round up their requirements - resulting in a lot of spare bandwidth on core network links. Most of these links need this spare capacity available, so they can temporarily accommodate traffic rerouted as a result of other parts of the network suffering downtime. When there's no downtime, such links are underutilised, so traffic prioritisation settings aren't making much of a difference.
Customers links to their MPLS service provider's core network tend to be similarly underutilised most of the time. As gigabit connection speeds become increasingly common, the need for traffic prioritisation will decline.
The need for MPLS Class of Service options to help reduce packet loss and latency due to contention is diminishing. It's still a good idea to use them, just in case congestion arises - but frankly, it's less important than it was when firms routinely had connections of 20Mbit/s or less.
The Shift Away from Copper-based Connections To Fibre-Optic Ones Is Cutting Latency
Prioritising traffic isn't just a matter of deciding which traffic has right of way on a given path through the network. It's also about picking the right path for traffic to take. Different traffic streams have different requirements. Some traffic is delay-intolerant, so needs to be sent through paths that minimise latency (delay) and jitter (variations in delay). Other traffic is less urgent and can be sent via slower, less direct routes to help the provider make better use of underutilised links in their network.
Copper-based services such as ADSL, FTTC, EFM over copper and EoFTTC are slowly being displaced by full-fibre alternatives, particularly when it comes to backup connections. This shift towards fibre is cutting the average levels of latency and jitter, diminishing the need to apply MPLS Class of Service settings to traffic travelling within countries such as the UK that are geographically small. For International MPLS networks, where long distances are involved, alternative routes may result in data travelling thousands of extra miles, so routing choices still matter a lot.
There is a countervailing trend to this reduction in latency. Firms are shifting server workloads from on-premise self-hosted self-owned single-tenant platforms to cloud-based provider-hosted provider-owned multi-tenant platforms. This adds latency to requests (as data now has to travel to and from an external data centre). This shift to the cloud is also creating network traffic (potentially risking congestion). Both of these will somewhat offset the benefits of the shift away from copper and growing connection speeds.
MPLS is Going To Be Hidden Away Because SD-WAN Is Trendier
Tech magazine Wired sometimes makes fun of the faddishness that surrounds technological and cultural trends by listing sets of three things - one that's trendy - 'Wired', one that's going out of fashion - 'Tired', and one that's far too old to be cool: 'Expired.'
Software-Defined WAN vendors and their partners are working hard to paint MPLS as Tired or Expired, while painting their own offering as Wired and massively cheaper than MPLS.
In truth, SD-WAN hardware can be costly, particularly if you have a lot of sites. It seldom offers the level of cost-saving being suggested, as in most locations broadband is an inadequate substitute for a full-fibre leased line - in particular, due to slower upstream speeds.
We suspect many MPLS providers will downplay their use of MPLS and jump on the SD-WAN bandwagon. We ourselves offer both options.
SD-WAN isn't really about cost savings. It's primarily about centralising control of an organisation's WAN and enabling more granular control over network use.
A single IT administrator can optimise connectivity at dozens or hundreds of sites, centrally. Important apps can be given priority over scarce bandwidth, while unwanted applications can be blocked from misusing the network. The bonding of different connections reduces the impact of connection downtime.
Getting a Quote for an MPLS WAN or an SD-WAN
To get a quote for a standard WAN, an MPLS WAN, or an SD-WAN, give us a call on 020 7847 4510.
