ITPRC NEWS - October 2000
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
So is MPLS ready for prime time? Check back this time next year.
For MPLS background information and resources, see our sister site: The
MPLS Resource Center -
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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