ITPRC NEWS - October 2000 - http://www.itprc.com/

MPLS - Ready for Prime Time?
By Irwin Lazar

It seems that one can't pick up an IT-related trade magazine these days without seeing some mention of MPLS. For those of you who haven't heard of this hot new technology, MPLS stands for "Multiprotocol Label Switching". Derrived from Cisco's old "Tag Switching" efforts a few years back, MPLS promises to bring all the functionality of ATM - guaranteed
QoS, traffic engineering, and traffic isolation, to IP-based networks. By converging ATM control plane functionality into IP, MPLS promises to reduce network complexity by eliminating ATM routing protocols and addressing schemes. Furthermore, MPLS offers the added benefit of being layer 2 agnostic. MPLS will function over PPP, ATM, Frame Relay and even Ethernet. This implies that end-to-end "virtual circuits" (or label switch paths (LSPs) in MPLS terminology) can be created on an end-to-end basis, regardless of the underlying media. Even more importantly, by removing the ATM layer, MPLS in theory allows network managers to remove the ATM cell restrictions and the inherent inefficiency in breaking up large packets to fit into ATM's 53-byte cells (known as the cell-tax).

Is MPLS ready for prime time? Many service providers including UUNET, AT&T, Global Crossing and Cable and Wireless are already implementing MPLS into their network backbones, primarily to control IP traffic to make use of under-utilized links (known as IP Traffic Engineering). Over time, MPLS-basd IP-VPN services should begin to appear. These services will use MPLS to create private connections across publicly switched networks,
bringing ATM and Frame-Relay like isolation to IP-based networks. In addition, since MPLS uses labels to make forwarding decisions, privately addressed networks can be tunneled within MPLS LSPs, which eases the pain of building IP-VPNs for organizations that are using private IP address ranges based on RFC-1918.

On the other hand, organizations such as Packet Design argue that MPLS is merely a short-term fix to a much larger problem, that is that IP routing protocols are based on decade old algorithms that need to be updated.

So far, the market appears to be solidly in the MPLS camp, with vendors such as Cisco, Alcatel, Nortel, Extreme and others either supporting, or planning to support MPLS within their products. But the true test of MPLS will come over the next few years as service providers attempt to scale the technology and overcome issues related to management and
interoperability. 

So is MPLS ready for prime time? Check back this time next year.

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For MPLS background information and resources, see our sister site: The
MPLS Resource Center - http://www.mplsrc.com/ 
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Irwin Lazar is a Senior Consultant for The Burton Group.  He focuses on strategic planning and network architecture for Fortune 500 enterprises as well as large service providers.  He is the conference director for MPLScon and runs The MPLS Resource Center  www.mplsrc.com and The Information Technology Professional's Resource Center  www.mplsrc.com.

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