MPLS in metro access networks

Irwin Lazar ILazar at
Thu Nov 15 18:00:54 UTC 2001

MPLS is also useful as a VPN provisioning tool in the Metro space,
especially to allow the provisioning of end-to-end PVCs regardless of Layer
2 transport.  For example, a service provider could use MPLS-VPNs to link
sites on its Ethernet MAN to sites on its DSL or Frame Relay services.

Also, you may wish to check out Riverstone's collection of papers on
Etherent, MANs and MPLS available at: and the MPLS Resource Center -


-----Original Message-----
From: srihari varada [mailto:varada at]
Sent: Thursday, November 15, 2001 11:12 AM
To: nanog at
Subject: MPLS in metro access networks


I have heard some stressing the role of MPLS in metro access networks.
It is difficult for me to visualize the need for it in them while it
is not so difficult to understand the utility (load balancing and fault
restoration etc.) of it in the metro backbone networks.

To characterize metro access networks in the context, the following is
-- aggregates traffic from residential (arriving via broadband access
   links such as xDSL, Cable) and business consumers (arriving via
broadband access links such as
   xDSL and high speed links such as Ethernet or SONET)
-- funnels aggregated traffic to metro backbone networks for destination

    hosts in the local metro region or remote regions across the
internet regional
   and backbone networks. Majority of such access networks are SONET/ATM
based (I didn't come
   across any case of Gig Ethernet. However, I do not preculde it).

Thus, there are two questions:
-- Are there known RBOCs/ILECs and CLECs entrenching MPLS in the said
   network scope? (I do not see many major ILECs in the un-official MPLS
   providers list being circulated but it may mean little)
-- If so, what motivates them to do so? Any analysis of the driving
forces is appreciated.


Srihari Varada

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