Thursday, January 28, 2010

Moving To MPLS Network Architecture From WAN Architecture

You're tasked with investigating if moving your company's network from a point-to-point T1 WAN architecture to a MPLS architecture makes business sense.

The easy answer here is yes.

But .... why?

In looking at changing your architecture from Point to Point to an MPLS type of network I suggest starting with the business requirements and tying your network requirements to the business needs. In this manner, you'll have clear business outcomes which you can negotiate back with you're business when you start getting the cost vs benefits discussion in developing your business case for investment.

A robust Total Cost of Ownership model will be needed to understand what the TCO will be gonig forwards. Also, I'd suggest developing a strong understanding of the costs of doing nothing and also the potential savings or new revenue opportunities for your business so you can develop a Net Present Value (NPV) of your network options.

I would also recommend looking at the interfaces you're looking to support in the network. MPLS does enable you to have a common protocol across all your networks and you can effectively establish an MPLS Cross Connect in your network. This will rely on how your local service providers will provide MPLS services to you, if at all. So you would most likely need to purchase either point to point or point to multipoint based transmission services from your provider. We're seeing that many enterprises and service providers are heading towards ethernet ubiquity as a service interface and then offering multiple services ontop of the ethernet interface.

VoIP works well across an MPLS type of network, however it does depend on the services that you purchase off your service provider. As you're looking at MPLS, then I assume that you're looking at buying straight transmission services and then you'll use MPLS to aggregrate traffic into your WAN links. Hence, you're business case is going to be driven by arbitrage opportunities so capture as much traffic as possible onto your network and apply QoS at the edge.

From a QoS perspective, ensure that you can also apply policing to the traffic that goes onto your WAN traffic. I recommend applying Heirarchical QoS as this will enable you to dynamically share the bandwidth in your WAN links.

As you can tell, there are lots of issues and questions that need to be addressed so I'd suggest working closely with some trusted partners and driving towards an outcome based business drivers and commercial outcomes.

We have worked with many customers that have migrated to MPLS from old school point to point. There are a few reasons our customers did this, but let me assure you the #1 reason was cost. A good competitive carrier will offer an MPLS solution that is sometimes less costly than the old point to point type solution ..... with most of the same or more functionality.

But there are some factors:

1. If the point to points are crossing state or lata boundaries ..... or are fairly separated by miles .... you should enjoy considerable savings.

2. If you get a carrier that bundles MPLS with an Integrated Access type solution you will save big money (combination of voice, internet & MPLS delivered on one T1 with quality of service).

Here's some additional points that might help you.

1. Is it redundant? Yes, depending on how you design your network (we can help you of course) sites can network with each other over your wide area network for disaster recovery/ redundancy. Unlike the traditional point to point architecture where you might only be as strong as that single link. We helped a huge national company with a migration from point to point and frame relay to MPLS. The big reason was with so many sites there was an outage almost every day. The network was designed with redundancy as the main driver.

2. Does it work as well? It depends who you ask. Are you talking to a salesman? He will say yes. Let me give you my "consultant" opinion. It works ALMOST as well but there are so many benefits to MPLS that typically motivate a customer to change. For example, if you have Quality of Service (QoS) sensitive applications running accross your WAN then you should consider MPLS. MPLS is a private networking technology similar to the concept of Frame Relay in that it is delivered in the "cloud". The primary difference with MPLS is that you can purchase quality of service for applications across your WAN. During the provisioning process the carrier (or your agent-wink wink) will interview you in order to determine which appications are important to your business, they will then build a QoS template to service these applications on your WAN. These applications will be given priority over all other traffic in times of peak load. MPLS is by far the most costly solution between Frame Relay, VPN and MPLS .... but is the only technology that will support QoS!

But let's put the salesman aside and remember one thing. With MPLS we are using the carrier's private network which is infinitely better than creating your own VPN. But because of some "overhead" and the belief that all carriers over-subscribe somewhat I am convinced that it's ALMOST as good.

So if it's almost as good would it be worth migrating if you could enjoy cost savings & redundancy??? Maybe. But these are the things that are making MPLS the hot ticket now.

3. Does this work well with VOIP? Sure. You can get QoS like I stated above.

MPLS is an IP-based framing technology (at OSI layer 3) that inherently meshes your WAN (this is the redundancy you refer to above). MPLS has a feature called QoS or quality of service. This feature allows both your CPE router and the carrier's network to prioritize data based upon your settings or preferences (carrier's level of support of QoS can be broad) and gives you more "bang for your buck" with the bandwidth that you select for the local loop going to each office. MPLS is made for VoIP like RC Cola is made for Moonpies. Because true "toll quality" VoIP requires prioritization across a carrier network, you (or your provider) can tag VoIP traffic with high priority to easily address the jitter and latency sensitivity inherent in the service.

The other huge advantage you have is that you can add locations with a simple routing table update and maintain a fully-meshed architecture, where with Point to Point circuits, you would have had to add a separate circuit to each location you want to interconnect, making MPLS more and more cost friendly the more locations you add.

Finally, MPLS allows you (or your carrier) to configure network objects (such as servers, VPN concentrators, and Network-Based Firewalls) as nodes on your MPLS network. For instance, with a properly deployed Network Based Firewall, you can provide all of your locations with an internet connection over your MPLS network that doesn't rely on a single location to aggregate the traffic. Some carriers even offer redundant firewalls, meaning that you have redundant Internet connections fully meshed giving you more potential up-time in the case of a single failure on your network.

What do you need to consider? In my experience, the biggest things to keep in mind are:

- Stay away from MPLS enabled Frame/ATM networks with committed access rates (CAR), this committed access rate is often a lower bandwidth than your local loop bandwidth, which can degrade your quality and quantity of bandwidth across a carrier's network (its always in the fine print).

- QoS at the "Edge" and across the "Core" - choose a carrier with both.

- QoS recognition across the carrier network - some carriers will allow customers to mark packets with priority, but will not recognize and uphold that priority, don't fall into this trap.

- SLA guarantees - be sure to choose a carrier that provides acceptable service level agreements for the type of service you plan to push across your network

- Customer Service and dedicated sales rep - you want someone you can reach out to with questions that you can trust - this is the most difficult thing to find.

For FREE assistance designing the right MPLS configuration for your network .... AND sourcing the most cost effective provider ..... take advantage of the help available via:

MPLS Networks

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