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So now let's jump in and take a more detailed look
at the different types of layer 2 VPNs that are available.
We're going to start off by looking
at a list of, really, two major VPN types and all
the different names that they share,
depending on the particular vendor or organizing body.
So let's go ahead and take a look at that.
And then, of course, we'll dig into those two types
in a little bit more detail to understand the differences
and how they work.
So let's go ahead and jump in, taking a look at that table.
So a sort of interesting aspect about layer
2 VPN types is these types actually
have different names depending on the organization, meaning
either the standards body or the vendor.
So if we bring up a little table here,
we have two major flavors of layer 2 VPNs.
We have the point to point, which the Metro Ethernet Forum,
or MEF, refers to as an E-Line.
Then we have the multipoint, which is referred to as E-LAN.
Now, just focusing on the point to point for a moment,
they're also referred to as Ethernet Private
Lines, or EPLs, Ethernet Virtual Private Lines, or EVPLs.
The IETF refers to these as the Virtual Private Wire
Service, which is how we referred to them earlier, VPWS.
These Cisco-specific terms over here
are actually pretty legacy.
But they also did refer to these as Ethernet Wire
Service, or EWS, and Ethernet Relay Service, or ERS.
The multipoints are referred to as Transparent LAN Service,
or TLS, Ethernet Virtual Connection Service, or EVCS.
Of course, again, earlier, we used
this term, the Virtual Private Lan Service, VPLS.
And once again, Cisco call these Ethernet Multipoint Service,
or EMS, or Ethernet Relay Multipoint Service, ERMS.
So again, there's two major types--
the point to point and the multipoint.
And even though we've been using the IETF phrasing up
until now, actually, the MEF names
are more commonly used today.
Again, the one I would say is really not
used at all is pretty much the Cisco terms.
But I would probably be familiar with the terms E-Line and VPWS
as well as E-LAN and VPLS, and know that those are effectively
the same thing.
Something else that's a bit important to discuss here,
as we're talking about connections
with the customer and different VPN types,
is the flexible ethernet mapping.
Effectively, what this does is it
allows us to process and classify various Ethernet frame
types.
We can do this either by EtherType field--
so maybe IPv4 versus IPv6, something along those lines.
Very commonly, we do this with a VLAN tag
to distinguish different types of traffic.
And we can also do it with the Class of Service field,
which is, of course, generally used for QoS.
Now, the reason this is important
to our current discussion of VPN type
is I could actually offer different VPN
types to the customer and have just one physical link going
out to that customer.
This service allows me to differentiate
between the traffic coming in on the interface from the customer
and therefore treat it differently.
Maybe it goes into one VPN that gets one type of treatment
or a different VPN that gets a different type of treatment.
Maybe it's different types of VPNs.
So it's important to be able to distinguish the traffic coming
from the customer in order to be able to put it
into the correct VPN based on the service
that they've requested.
Now, on the Cisco ASR 9000 Series
and a couple of other platforms, this
is referred to as an Ethernet Flow Point, or an EFP.
Each of these flows from the customer--
or you could call it the access side--
is mapped or connected to a service on the trunk side.
This is what's allowing us to offer different services,
maybe put them into a separate VPN, that sort of thing.
The Customer Equipment or the CE, device
connects to the carrier Ethernet network,
which is, of course, the service provider network,
using the UNI, or the User-Network Interface.
The UNI is essentially the interface facing the customer.
That would be on the PE router.
And we did mention this before that the attachment circuit
is between the CE and the UNI or the PE interface.
So again, the two major types--
first, we have the point to point, or the E-Line.
This can actually either be locally connected, which
would be two EFPs on the same platform using
native Ethernet-- so basically, if you had a customer connected
to the same PE and you needed to connect their two
sites together.
More commonly, of course, we would
be doing Ethernet over MPLS.
This is going to involve those two EFPs but this time
on different platforms.
And the connection between them is
going to be using Pseudo Wires, or PWs.
So that's two different ways of offering the customer
a point-to-point connection.
For point to multipoint, or E-LAN, again,
there's still sort of two ways.
One is we could do local bridging.
This would be two or more EFPs on the same platform.
And it's going to use, again, native Ethernet.
But we're going to put this into a bridge domain.
If you're not familiar with a bridge domain,
it's effectively a layer 2 broadcast domain.
This is actually very similar in concept to a VLAN.
But it's just a construct on the device that
lets us put multiple interfaces into a single layer
2 environment, where all the devices can communicate
with each other without necessarily
carrying that stigma of a VLAN or a VLAN tag.
But overall, it's the same sort of idea
that they're all in the same layer 2 broadcast domain.
When we get to VPLS bridging, we'll
notice, once again, it's almost the same idea here,
where it's two or more EFPs.
This time, of course, they're on the different platforms.
But they're also in a bridge domain.
These are then connected with a full mesh of those pseudo
wires.
That's what's going to make it a multipoint connection.
So in this video, we took a more detailed look
at the different types of VPNs that we have available.
Just to be very generic about it,
it's essentially point-to-point or multipoint layer 2 VPNs.
Those are our two major categories.
So now it's going to be time to jump into more
detail on each one of those.
So we're going to start with VPLS.
We're going to start off by talking
about the details on that type of VPN.
And that's exactly what we're going to do next.
Until then, I hope this has been informative for you,
and I'd like to thank you for viewing.