Friday, July 27, 2007

MPLS.....The Next Generation Of Communications?

MPLS appears to be the next generation of communications. There are numerous applications that can take advantage of this latest technology in being able to prioritize data packets by assigning labels to them. Of course, it's still in the "early days".

MPLS is what ATM should have been. All the traffic control of ATM, without the limitations of fixed cell sizes. In general where you want to manage services with different QoS, MPLS is the right answer for high bandwidth pipes, ATM is the right answer for low bandwidth pipes (which is why it is used for DSL).

Lots of products have the label MPLS, but beware - there are several partial implementations (Cisco included) of the MPLS specifications, many of which do not give the full range of QoS and hence support for carrying diverse services at the same time. For multi-service networks MPLS is what I would be basing the networks on today - but please check the small print to ensure they do actually do what you want.

I would say that MPLS is the 'Now' (not the Next) Generation of backbone technology. In Europe and AsiaPAC it is already the technology of choice for most new WAN implementations.... and the number one service offering from most Global Telco's, not to mention the main focus of Vendors.

My only caution would be to not forget to compare the business cases for MPLS and competing legacy technologies when considering a change. Often the Service Providers push customers into MPLS because it is fashionable and the margins are better for them as they can bundle multiple services with it (Data and VOIP plus enhanced network monitoring tools etc). Whether MPLS 'costs in' for a customer will depend on:

(a) existing and future bandwidth requirements;

(b) the need to flex bandwidth on demand;

(c) geographical spread of WAN (distance from the exchange and regulatory restrictions).

There have been instances where companies have been halfway through the rollout of an MPLS WAN....only to realize that they are going to spend more (not less) on a technology that they won't really benefit from. Also some companies have ditched MPLS when they realized that they could double their existing ATM bandwidth cheaper and faster in some locations....rather than deploy MPLS.

Overall though, with (a) the refresh of network infrastructure now better built into operating budgets; and (b) the realisation that things like VOIP and convergence of legacy and current data networks are no longer a leap of faith; as well as (c) the removal of premiums for MPLS services - it is truly becoming the default technology for todays Wide Area Networks.

British Telecom as well as all the other UK, European and US Telcos I can think of, all deploy MPLS as their carrier backbone technology. It is highly likely that if you buy ATM in some locations today it will be encapsulated over MPLS anyway!

Every major telco in the US is pushing MPLS. In fact, Sprint is abandoning the frame relay service at the end of the year and getting everyone on their MPLS network.

Just remember that you have to have MPLS at every site in order to full take advantage of the technology. However, from the US, every telco ATT, Sprint, Verizon, GX can offer the service globally.

Just a side note "Aw Ha moment"....the cost reductions touted however, depends on your network topology as well as the Telco being used.

For example.......

Sprint: Moving from a traditional frame relay network to an MPLS network will save you money. IF you have a fully meshed frame relay network the savings is greater. Why? Because with Sprint the Class of Service is free. So you go from loop + port + PVCs to loop + port.

Verizon Business: Verizon offers CAR (Commmitted access rates) with their MPLS offering (Private IP or PIP). So you don't have PVCs, but now you ahve to pay for CAS depending on what you want it can be the same or more.

ALL MPLS offerings allow clients who previously did not have a full meshed network to now have the benefits of one. This plays well into most clients Disaster Recovery plans too.

Now....on a devil's advocate approach to the hype of MPLS.

Firstly, MPLS provides CoS (class of service) not QoS which ATM "does" provide for true clarity of the subject. The problem I've seen and dealt with surrounding MPLS is its implementation. Its touted as a "cheap" - or lower cost (word this how you'd like) solution to ATM and it is to a degree (equipment wise) - but its also a different service.

Now, for MPLS to be effective, your entire route from point A to point B has to be MPLS enabled. So given locations A say in England and location B in say Chicago, this entire path from both locations have to (emphasis on HAVE to) be MPLS enabled. Or else, your packet markings are useless.

Here is a sample packet flow:

VoIP Call from London --> Provider A (MPLS)
Provider A --> Upstream --> Upstream's Provider (No MPLS)
Upstream's Provider --> Back to Location A (No MPLS)

Since the Upstream's Provider doesn't have MPLS enabled, anything you "think" you made better was worthless. Those MPLS 6509's and better you configured, made no dent in your traffic speed, saved you zero dollars.

Static routing?.....MPLS is highly dependent on static routes, routes flap, routes go down. Fact of life. MPLS is brutally dumb and takes an insane amount of configuration on the engineers for failover scenarios.

QoS?.....Same applies, you could color your packets a rainbow of colors. If the upstream or anyone in the path strips those colors, its a wasted effort. Vendors - especially bandwidth vendors - won't make mention on how MPLS is not all that its cracked up to be. They'll pitch you a product. "Fastest bandwidth on the planet". But unless the locations are strictly on that provider's network. There is no guarantee from another provider they will honor any colorings of packets (QoS/CoS) of MPLS or ATM. Outside of that...... MPLS is IP based and succeptible to all kinds of attacks. At least with ATM the attack vectors are slightly more difficult.

Now that you're thoroughly can make the decision for MPLS (or not) even easier by using an unbiased consultant. My number 1 recommendation is to take advantage of the free services at .....

MPLS Applications


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