Feature

MPLS: The Importance of Access Choice

Tom O’Hagan, Managing Director of Virtual1, examines why in his opinion MPLS has to be the technology of choice when it comes to building wide area networks.

MPLS really has to be the technology of choice when it comes to building a Wide Area Network. There has been some dissent from some providers who believe that VPLS offers the same flexibility and capability but at a cheaper price, but this just isn’t technically accurate. Whilst the basic technical capabilities are fairly comparable – overall capacity, for example, or the ability to carry multiple types of traffic – VPLS simply does not have the scalability that MPLS can offer, nor the international geographic coverage, and at Virtual1 we consider it only for niche cases.

However, in my experience, whilst a debate about which transport technology is the most appropriate may occasionally occur, what is more important is the choice of access method for each individual site. After all, it is the access method in combination with the core technology that defines the true capabilities of each individual network.

One of the beauties of an MPLS network is that you can use any access method available at the site:  DSL, FTTC, EFM or Ethernet – all will allow you access to the MPLS network.  You can even use a different access method at each site. But these technologies are very, very different in their capabilities and a common issue we find is that businesses don’t really take this into account in enough detail – and are then frustrated when their network cannot deliver what was expected.

Much of this stems from the common misconception that what is important is capacity, that so long as there is enough capacity, everything will work as it should. Unfortunately this is not so. For example, FTTC offers speeds of up to 80Mb, which is more than enough to run both voice and data over the network. But FTTC is still a copper-to-the-premises product; it might well suffice for a home VoIP solution but, with no direct control over issues such as latency and jitter, a business-grade voice solution cannot be run effectively.

The need to address is this becoming greater now that businesses are beginning to move their applications to the Cloud. If your customer’s services and applications are hosted centrally in a datacentre then remote access to them needs to be fast and reliable to ensure the user experience is seamless. This means ensuring your access technology offers guaranteed latency – making Ethernet the only possible choice. Yet still we see businesses trying to access cloud services over nothing more than an ADSL connection. Hardly surprising then that businesses are finding cloud migration frustrating.

Backups are another area of concern. For example, one of our Partners recently suggested using ADSL backup for an EFM site. Normally this would be fine as it would enable the business to remain connected, albeit at a slightly slower speed. However, through discussions with the end customer, we knew that voice traffic from this site was also being run over the network – the main reason for using EFM in the first place. With only an ADSL backup in place, the voice traffic would be at risk, because, as with FTTC, you cannot prioritise traffic end-to-end on an ADSL circuit.

This solution wasn’t necessarily wrong, but it was essential the customer knew and was happy with the fact that the voice traffic wasn’t protected.

And that is the crux of the matter. Our job is to deliver a network that does what the customer expects it to – and if it doesn’t either through lack of communication or lack of qualification, then the blame lies with us. But this no bad thing - instead resellers should view this as an opportunity to differentiate themselves: by understanding not only the demands that will be placed on the overall network but understanding the needs of each site and recommending the correct access method to ensure those needs are met, resellers will position themselves as true network experts, and trusted partners on which their customers can rely.

MPLS Defined:

MPLS is a highly scalable, protocol agnostic, data-carrying mechanism. In an MPLS network, data packets are assigned labels. Packet-forwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. The primary benefit is to eliminate dependence on a particular OSI model data link layer technology, such as Asynchronous Transfer Mode (ATM), Frame Relay, Synchronous Optical Networking (SONET) or Ethernet, and eliminate the need for multiple layer-2 networks to satisfy different types of traffic. MPLS belongs to the family of packet-switched networks.