Metro Ethernet, VPLS clarifications

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1

Hi experts,

I need some clarifications on these terms. Could somebody give explanations or share some links?
When and how are these technologies used?

Thanks in advance.

2

Metro-Ethernet is generally the term used to describe Ethernet used as a
WAN connection or as a point to point connection. There was at one time
the concept of a MAN (Metro Area Network) but "metro" ethernet is now
available in more scenarios than that described. The connectivity can be
over fiber or copper and the speed delivered can be as low as a few mbps
but commercially available offerings normally start at 5-10 mbps. On the
high end its possible to get gigabit and faster connections in certain
areas.
http://en.wikipedia.org/wiki/Metro_E

VPLS stands for Virtual Private Lan Services. This an umbrella technology
that allows for the bridging of layer 2 traffic across various layer 2 & 3
networks. This is generally used as a replacement for a point to point
metro ethernet (or other) connection.

http://en.wikipedia.org/wiki/VPLS

3

05.02.2013 19:58, Scott Helms ???:

Metro-Ethernet is generally the term used to describe Ethernet used as a WAN connection or as a point to point connection. There was at one time the concept of a MAN (Metro Area Network) but "metro" ethernet is now available in more scenarios than that described. The connectivity can be over fiber or copper and the speed delivered can be as low as a few mbps but commercially available offerings normally start at 5-10 mbps. On the high end its possible to get gigabit and faster connections in certain areas.
Metro Ethernet - Wikipedia

VPLS stands for Virtual Private Lan Services. This an umbrella technology that allows for the bridging of layer 2 traffic across various layer 2 & 3 networks. This is generally used as a replacement for a point to point metro ethernet (or other) connection.

Virtual Private LAN Service - Wikipedia

    Hi experts,

    I need some clarifications on these terms. Could somebody give
    explanations or share some links?
    When and how are these technologies used?

    Thanks in advance.

    -- Regards,

    Abzal

--
Scott Helms
Vice President of Technology
ZCorum
(678) 507-5000
--------------------------------
http://twitter.com/kscotthelms
--------------------------------

Thank you, Scott and all of you for your answers and time.

Standartized technology that allows to connect multiple different networks. And it is independent from physical and datalink layers. And nowadays which tecnology is the most used(VPLS or Metro)? What about MPLS? Sorry I'm a little confused. I really want to understand.

4

The Metro Ethernet Forum (MEF) develops standards for Metro Ethernet, which
are generally implemented by telcos/cablecos. See the following link:

http://metroethernetforum.org/

The 2 biggest problems I have found with telco/cableco MEF services are:

1. In network configurations where all sites are relatively close together
(< 500 miles), the telco/cableco SLAs are meaningless, bordering on being
fraudulent. For instance SLAs of 50 ms round trip for bronze service, and
20 ms for gold service are enough network transit time to send packets 5000
miles and 2000 miles respectively. This is like buying homeowners'
insurance on a $500K house with a $10 million deductible (50 ms SLA), and a
more expensive policy has a $5 million deductible (20 ms SLA).
2. The MEF spec does not address directed multicast, as opposed to a native
Ethernet switched network which updates the mac tables with each next hop
for the multicast requestor (video for instance) tracking the Layer 3
multicast routing protocol shortest path. So in MEF implementations where
users view a constant 10 Mbps (for example) multicast video stream between
a requestor and a multicast source, this 10 Mbps gets broadcast out all
switch ports in a users' MEF VLAN, rendering low speed MEF connections at
all other users' locations useless.

David

5

From my understanding M-Ethernet is a some kind of service. Standartized
technology that allows to connect multiple different networks. And it is
independent from physical and datalink layers.

Metro Ethernet is a datalink (layer 2) protocol. It also has physical
(layer 1) specifications though there are several kinds of physical medium
that can be used. Most commonly its delivered over fiber (single or
multi-mode depending on distance from the last active element) or cat 5E/6
twisted pair.

And nowadays which tecnology is the most used(VPLS or Metro)? What about
MPLS? Sorry I'm a little confused. I really want to understand.

VPLS can be run across several different kinds of layer 1 & 2 technologies
and is independent of the underlying technology because it builds it pseudo
wires at layers 3 & 4. VPLS leverages technologies like Metro Ethernet and
MPLS to extend a business' Ethernet LAN (technically the broadcast domain)
to remote sites. At the end of the day you can use several kinds of
tunneling technologies to provide VPLS, including GRE, MPLS, and L2TPv3.

Here are the main two RFCs:

6

Hi,

My 2 cents

VPLS can be run across several different kinds of layer 1 & 2 technologies
and is independent of the underlying technology because it builds it pseudo
wires at layers 3 & 4. VPLS leverages technologies like Metro Ethernet and
MPLS to extend a business' Ethernet LAN (technically the broadcast domain)
to remote sites. At the end of the day you can use several kinds of
tunneling technologies to provide VPLS, including GRE, MPLS, and L2TPv3.

For fun you can also do :
  LDP VPLS over a GRE tunnel
  LDP over a GRE tunnel within an encrypted network

I can be wrong but VPLS is running over MPLS (rfc 4762) because it is using LDP

Regards

Fabien

7

And for fun you can also do:
Ethernet over PBB to VPLS
Ethernet over PBB over VPLS -that's actually called EVPN

adam

8

I thought that PBB was dead :slight_smile:
if not forget VPLS and play with PBB and PBT :slight_smile:

Welcome in the "twilight zone"

Fabien