There are many different deployment models that we might consider when we are
deploying
our wireless architecture.
And this has to do specifically with, again, the wireless LAN controller
location, but
it also determines the number of wireless LAN controllers we're going to deploy
.
So let's just start with the first model, which is the centralized model.
In a centralized model, we are ideally going to just deploy a single redundant WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
In a centralized model, we are ideally going to just deploy a single redundant
wireless
LAN controller instance.
Now with redundancy, we have two choices.
We could deploy two separate wireless LAN controllers and some amount of access
points
connect to one, some amount of access points connect to the other, and if one
of these
goes down, then we hope to swing those access points from the first down to the
second.
There are a lot of challenges with this.
For example, if I'm deploying a redundant pair, each of these needs to have not
only the
hardware, but the licensing for full support. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
hardware, but the licensing for full support.
Because if one of them goes down and we don't have the ability to support all
of the access
points, then it wasn't a very redundant model.
This is more of a legacy type of architecture because it was just what we had
to do for a
long time.
But now Cisco does support the concept of a high availability pair, meaning
that I still
have to spec out the hardware that's going to be able to support all of the
access points.
But there's a couple of interesting changes. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
But there's a couple of interesting changes.
First of all, I deploy both of these sets of hardware together and then I
connect them
in a special way so that they are one configuration and ultimately one logical
wireless LAN controller.
This fits that conversation we had earlier about Stackwise Virtual, Stackable
Switches, Chassis
Switches.
We're combining two physical components into one logical one, meaning that I
only have
to configure one. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
to configure one.
I only have to license one.
And at that point, if all of these access points that are connecting to the
primary, if
the primary fails, then they will automatically switch over to the secondary
because it's
one configuration.
It's using the exact same IP address.
Whereas before, each of these were independent and they each needed their own
IP address.
So the HA pair is a wonderful way to deploy a centralized model because I can
deploy again
one logical wireless LAN controller. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
one logical wireless LAN controller.
And I just connect all of the access points into in my entire environment back
to this
central pair.
So, yeah, I guess as we talk about the pros and cons, the pros of this is it's
very simple,
especially simple to manage.
Management, simple to management, simple to manage.
But the cons is the location concept, which is where are we going to deploy WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
But the cons is the location concept, which is where are we going to deploy
this?
The previous conversation there, we said that maybe it makes sense to deploy
this into
the data center, except it doesn't because we don't want the wireless clients
living in
the data center.
So, where are we going to deploy it?
Well, I could deploy it into one of my distribution closets, but I might have
lots of distribution
closets and network blocks in the network.
And so, this works well for the local access points here to connect to the
distribution
LAN connect. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
LAN connect.
But now all of the access points over here need to come over to this other
building in
order to access the wireless LAN controller.
Does this work?
Sure, it does work, but all of the wireless stations out here are now going to
belong to
subnets that are attached to this distribution layer.
So, it centralizes, yeah, the hardware and the management of that hardware and
that's
great, but also centralizes our wireless subnets.
So, all the wireless subnets in our entire organization now live logically in WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So, all the wireless subnets in our entire organization now live logically in
one location.
So, this might lead us to the distributed model.
The distributed model is going to flip the centralized model on its head.
It's going to allow us to have many wireless LAN controllers and these wireless
LAN controllers
are going to be smaller because they're only going to service their own sites.
So, again, imagine that I have multiple distribution blocks.
Maybe I have three different locations. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Maybe I have three different locations.
These are all my distribution locations, so I deploy a HA pair into each one of
these
distribution layers.
Now, the advantage to this is that my access points here can connect up to
their local distribution
layer to communicate with the wireless LAN controller.
Furthermore, all of the wireless stations that are downstream here, all of the
stations
also attach to subnets that belong to the specific location. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
also attach to subnets that belong to the specific location.
And so, this really fixes a lot of our issues with the logical side of things.
For example, the wireless subnets living in a different place and potential
latency
issues trying to communicate to another location.
The downside to this is that I as the admin now have to log in to lots of
wireless LAN
controllers and manage many configurations.
And this can make us as an admin very, very sad because now we have to manage WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And this can make us as an admin very, very sad because now we have to manage
all of these
different configs.
The upside to this is that there are software solutions out there, especially
in the Cisco
world.
We can think of Catalyst Center as being an option for us to now manage the
software and the
software pushes configuration down to all of the controllers for us.
But it does, even in that situation, complicate the network a little bit.
From a management perspective, we have to manage all of these locations. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
From a management perspective, we have to manage all of these locations.
We also have to individually manage the licensing and the hardware.
And, you know, there's upsides and downsides to both models.
We just have to weigh which one we want to really think about.
Now on top of all of this, we need to think about our remote sites.
Our remote sites usually don't warrant having their own wireless LAN controller
on site.
For example, I might have a small location that has three access points. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
For example, I might have a small location that has three access points.
What am I going to do about this small site?
I've got a switch that has connection to all of these APs.
And this goes through some kind of router and I've got a single wide area
network link that
takes me back to the rest of the network.
Do I need to deploy a very small wireless LAN controller here?
Probably not.
But I could.
I mean, Cisco does make them very small.
We could deploy a small wireless LAN controller here. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
We could deploy a small wireless LAN controller here.
But as we talk about this distributed model, we might already have half a dozen
wireless
LAN controllers out there.
Now I have to deploy one to every one of my remote sites.
I could end up with dozens of wireless LAN controllers.
So first and foremost, we could connect out to a remote distribution closet or
just our
centralized option.
If we choose that, connect out to wireless LAN controllers that are remote.
We can absolutely do that.
It will work just fine until what happens in what we said in the last video WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
It will work just fine until what happens in what we said in the last video
happens where
the WAN link goes down.
This is where we really could use a local wireless LAN controller because then
our access
points stay online, which might matter if we have a separate internet circuit
here that
way users can still get out to the internet even if they can't get to the rest
of the network.
Now funny enough, that is a conversation because if the internet lives out the
WAN link, we
could argue that it's not a whole lot of value in maintaining our wireless
network at that WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
network at that
point.
Unless we have wireless phones and we need to make emergency calls, but lots of
conversations
need to be had around the resiliency level that we're expecting.
But if we don't want to deploy wireless LAN controller here, we can take
advantage of
Cisco Flex Connect, which is typically what we want to do in these locations.
Flex Connect, as we said before, allows for us to lose the wide area network
and the access
points stay online.
Now if we have a very small remote site or maybe more to the point of very WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Now if we have a very small remote site or maybe more to the point of very
small organization,
we could technically look at an autonomous solution.
This is not the best solution in most cases.
Again, each access point has to have its own management and that's not just an
IP address,
but also radio management.
I have to individually manage every channel, the transmit power of every AP.
And we said earlier that yeah, this was how we had to do it once upon a time, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And we said earlier that yeah, this was how we had to do it once upon a time,
but really
we shouldn't be deploying it today.
So this has a place for very, I'm going to say even very small organizations
because if we
have an organization with fewer than 10 access points, then it might make
sensors deploy
it to that or deploy an autonomous solution rather than going with deploying an
actual
lightweight controller.
But we might actually prefer to look at another solution, which can apply to WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
But we might actually prefer to look at another solution, which can apply to
very small
and very large deployments and that would be the concept of the cloud.
So we do have cloud managed solutions.
And at this point, I'm specifically thinking of something like Cisco's Miracchi
product line,
which allows me to simply connect an access point to the network.
And as long as it can get out to the internet, then it can receive its
configuration and it WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
configuration and it
can remain online and all of these things.
Now we do not use capwap in this case.
So we don't have to worry about our traffic getting tunneled out to wherever
the cloud is.
And so it simplifies things that way.
I don't even have to worry about the hardware and licensing considerations of a
wireless
LAN controller.
I just purchased one license per AP.
I plug the APN, it connects up to the wireless system. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
I plug the APN, it connects up to the wireless system.
And regardless of how many access points I have, I have a single point of
management,
which makes me as an admin very happy.
So the cloud managed solution is actually very popular.
Cisco's got both solutions and whether we are trying to figure out what to do
with a wireless
LAN controller or we just want to go simple and go with cloud managed.
Well, it's just going to depend on the organization of what exactly we're
looking for. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
looking for.
But either way, we can take a look at all of these different models and try to
figure out
what the best model is for our organization, not only based on our size, but
also based
on the current architecture that we have in our environment.