MPLS in metro access networks

Michael Cohen mcohen at
Thu Nov 15 16:44:34 UTC 2001

And I'm not sure what faster switching/routing has to do with MPLS:)  I
believe one of the ideas behind MPLS benefiting metro access networks is
using MPLS to deliver layer 2 VPNs across an MPLS enabled core thus
simulating leased lines for access clients...but I'm sure somebody will
correct me if I'm wrong.  There seems to be some hype for Martini draft VPNs
and large enterprise customers in metro areas.


-Michael Cohen

-----Original Message-----
From: owner-nanog at [mailto:owner-nanog at]On Behalf Of
Quibell, Marc
Sent: Thursday, November 15, 2001 10:20 AM
To: 'srihari varada'; nanog at
Subject: RE: MPLS in metro access networks

I would think faster switching/routing and less processing would be wanted
in any mid-to-large sized network...I'm not sure what load balancing and
fault restoration has to do with MPLS....


-----Original Message-----
From: srihari varada [mailto:varada at]
Sent: Thursday, November 15, 2001 10:12 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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