Applications of MPLS in the metro area

Hello !

I’m looking for what a network operator would consider a realistic reference deployment of MPLS within the metro area network.

By “realistic reference”, I’m asking about what a network operator would consider to be a typical, perhaps most common, application of MPLS technology.

From a bookish perspective, I understand MPLS well but have never implemented it in the scope of my current field of study (metro area networks). I would dearly like to get this “grounded” perspective from anyone who might care to share it.



For the ISP and Carrier Ethernet network I run, I use MPLS for various things.

It provides wonderful segmentation of different communities (customers and uses).

I use MPLS ELINE (p2p) extensively for Cellular Backhaul

I use MPLS ELAN (mp2mp) in various places for emulating LAN’s over long distance

I use MPLS L3VPN for various things…

  • Containing customer public internet routing

  • Containing customer cgnat private side

  • 6VPE for getting IPv6 across my ipv4-only core



So where the books talk about PEs -think of your metro nodes here (basically converting the metro into an MPLS network -or making it part of your existing MPLS core) (you might not have a classic design where PEs hang off of P-Core nodes and might have just rings of PEs in your metro area)

And where the books talk about various L3VPN and L2VPN services that’s basically what you can offer over your metro -now that it’s been converted to a fully-fledged MPLS network.

Ranging from multicast L3VPNs for 3PALY services through L2 p2p|p2mp|mp2mp services for Dat-Center-Interconect, to network-slicing buzzword (cause with VRFs and Traffic Engineering you can slice your metro area network whichever way you like).


Yeah, I forgot earlier but I’m using EVPN/MPLS for DC interconnections now also, for nicely integrating L2/L3 and host/machine level route preference

MPLS in some ways is reminiscent of the ability to fire-off Smart-PVC’s (SPVC/P) over an ATM (asynchronous transfer mode) network, and thus achieve end to end virtual private connectivity without touching the intermediate nodes (p nodes)…. Since the p-nodes just do label swapping (like vpi/vci swapping in the atm analogy)

In actuality, many of my “p” nodes, are also “pe” nodes J it’s all about what it’s doing at that moment for what it is that we are talking about


I started poking around to learn more about these use cases and came across this interesting extract:

“Juniper Networks ACX Series Universal Metro Routers are Juniper’s response to a shift in metro network architecture, where the access and aggregation layers are extending the operational intelligence from the service provider edge to the access network.”

Not long ago, I used to think of anything above layer 2 as “service provider edge” and further still (away from access), but the responses I’ve garnered are pointing at a metro network that widely implements MPLS and access and aggregation segments that are seeing implementation of L3 functions.


Yeah, I use the heck out of the ASCX5048, it is the mpls edge of my resi/busi mpls ftth network…

Lines/terminology can get blurry…But, I would say that I will do my best to get mpls into every nook and cranny of my network, where/when it makes sense.

Forgive the atm analogy again, but seriously, when I managed the US Navy ATM Network in San Diego (2000-2004) I wanted cells into every nook and cranny in order to benefit from all the virtual capabilities atm had to offer…

…same with MPLS…

…I’m increasingly hearing about devices like cisco’s ncs540, that enable mpls into smaller edge boxes, so that you can make use of up-and-coming sr/spring/evpn (mpls-based apps), automation, etc, etc


…juniper did a write-up on us :slight_smile: