So this awful typology of a U.S. 420 and I'm going to connect three IP phones to the U.S. 500 now I'd
like to demonstrate the power that the phones receive the three phones that we have in this typology
are 79 71 79 60 and a 79 65.
And what I'd like to demonstrate is the amount of power that these phones use.
And let's see if they use POPC or ADA 2.3 A-F as an example 79 60 phone has been around for many years.
And this particular phone only supports P.O.D. that does not support Ada 2.3.
So once again you have to be very careful with your power.
You've got to make sure that the switch or device providing power supports the power that the phone
requires.
In other words edited or 3am or for instance a or 380 or Cisco's power of Ethernet.
So lets connect to the device and see what happens.
So I'm going to tell it to these 500 and log in the C'mon show power in line will show me the power
usage at the moment.
You'll notice that none of these ports if 0 1 0 2 0 1 7 are powered noticed power allocated is zero
what's on all of these ports the max amount of power that this switch or in this case use the 500 supports
is 88 what's also note that the ports have been configured for Orta allocation of power.
Once again you would never set a port on full power.
It's either auto or it's off.
So just to show you that on a port I'm going to go to one of the interfaces and topic them on power
in line and notice the only options auto or never.
So we'll just leave those ports at quarter power allocation at the moment no phones are connected.
I'm going to enable Terman so that we can monitor what's happening.
Even though we telnetting and I'm going to plug in the phones so let's see what happens.
As you can see the interfaces are coming up.
So if I do the same command again show power line.
Now it is at the moment two ports are showing the allocation of I triple E plus three power and the
power allocated is 12 watts for the one phone and fourteen point nine watts for the other phone.
I'll do the KM on the game.
And notice 6.3 Watts has been allocated to the phone on a one slash two and it's using Cisco's power
over Ethernet.
Doing that come on show SCDP neighbor will allow me to see my neighbors.
You can see that we've got IP phones on port 1 2 and 3 let's look at the details so as part diagram
if one slushed to as the 79 60 connected to it.
So once they get to the 79 60 connected to it on forced Ethan it's 0 1 3.
The 79 71 is connected on if the 0 1 1 the 79 65 is connected
show Paula inline rather shows me that the 79 65 is drawing 12 watts of power.
The 79 60 is drawing 6.3 watts of power and the 79 71 is drawing fourteen point nine watts of power
initially in a class 3 device starts up.
So a device that requires added or three if it will use 15 watts of power.
But through CTP the phones negotiate the amount of power that they require and that's what you use less
power or more power.
So to demonstrate that I'm going to shut the interfaces down and then no shut them
so you can see the interfaces went down not tapping to come on to show power in line shows me that there's
no power allocated on no shut those ports do they come on again.
And as you can see they fifteen point four watts of power was allocated to those two ports.
Notice fifteen point four watts of power is allocated to all three ports and now they negotiate the
amount of power that they require.
So the 79 65 has gone down to 12 Fort's the 79 60 down to 6.3.
And let's see that 79 71 will eventually go down in its power requirements.
Now it's taking a while.
So I'll just pause this and wait.
So after a while you'll notice the following.
It was originally fifteen point four watts and then went down to fourteen point nine watts of power.
You can see the maximum available is 88 that city 3.2 have are been used whereas previously just thirty
three point seven before the iPhone successfully negotiated.
Buy a CD with a switch that it required less power.
Once a phone has power the next thing it needs to work out is which of the lan it's configured on.
You can manually configure be lands on Cisco IP phones but in most implementations in the real world
the deal any information would be configured on the switch and the phone would query the switch either
using Cisco discovery protocol or CTP or link delay discovery protocol or else LDP LDP is an industry
standard protocol equivalent to CTP for Cisco IP phones.
The actual LDP version used is L-L DP med the med standing for media in point discovery which is an
enhancement to the standard LDP so the phone will query the switch and find out which villain it belongs
to.
There are multiple ways for connecting a phone and PC to a Cisco switch or other vendor switch.
Once again just note CTP would be used between Cisco phones and Cisco switches.
LDP would be useful since between a Cisco phone and an HP switch.
Newer phones would use LDP between the Cisco phone and the Cisco switch.
I sampled Knology before allocating villans to interface's.
We need to decide which villans to create and what subnets to allocate to those villains.
So we're going to have a data villain and a voice LAN.
Now to give this example very simple we are going to configure Bil'in one as the data villaine with
a subnet of 10 1 1 0 slice 24 and the voice LAN with relend to a subnet of 10 1 2 0 slash 24.
Now in the first example we are going to have the PC and the phone in the same villaine.
That's not recommended.
Cisco would recommend that you put your PCs and phones in separate the lens and thus in separate subnets
so I'm going to telnet to the U.S. 500
into a global configuration mode and create a villain to the last one if you remember exists by default.
I'm going to give it a name or description of voice the land.
I can go back to privilege mode and then top the C'mon show then.
Now new U.S. 500.
It's acting as a robber and as a switch.
So to see the villains on the switch ports you need to top tap the C'mon Chhobi let's switch now as
you can see here.
Interface's if 0 1 0 up to the 0 1 8 on the line 1 default the line no interfaces are in the voice villaine
now the first way to implement the plans is to have a single land access port.
This is essentially where you've got a PC and a phone connected to a port on the switch and they both
within the same deal and so this port is configured as a standard access port.
There is no trunking and no tagging untagged frames are sent to the phone and violently and untacked
frames are sent to the PC on the Leonti.
There is no special tagging or differentiation between frames belonging to the PC and frames belonging
to the phone they both belong to the same Bil'in.
There are some disadvantages to implementing phones in PCs in this way.
The first issue is security.
The pc will be able to sniff traffic from the phone and be able to record the voice conversation.
If an application like Cain and Abel is used on newer phones that functionality can be disabled by the
sea UCM for example Callia service is also harder to implement because you cannot differentiate between
the traffic types based on Bil'in.
There are two scenarios where you may have to set up a single violent access port.
The first one is when you've got a soft phone or in this example the Cisco IP communicator running on
your laptop.
In this example both the softphone and the PC are in the same plan because the Sophonias running on
the PC.
So traffic going to the PC and traffic going to the cellphone are sent across the same port untagged
in the same villain.
The second example of using a single villaine access board is when you've got a non Cisco IP phone solution.
In this example you may need to configure the phone and the PC in the same Bil'in.
However that is less common these days as most phone vendors support the concept of a voice of the land.
But if you come across an older solution or a smaller vendor you may need to implement your villans
in this fashion.
You set up a single Bil'in access board on this page you're simply going to need to face
Antarctica on switchboard mode access switchboard access the LAN to whichever LAN you were going to
use to view the configuration I can top that can on do a show run interface if 0 1 slash 1.
And as you can see they this is just a standard code configured with a standard villain.
It's configured in the same way you would configure it if there was just a PC connected to the port.
Once again this is not recommended that you may need to do this if you've got non Cisco phones connected
to your switch.
I could also do the command show interface if 0 1 slash 1 switchboard.
And notice here you can see that it's being configured for static access.
The operational mode is static access the access villanies violent too and no voice feel and has been
configured.
So this is just a standard access port.
In the old days you used to connect Cisco IP phones to the network infrastructure using trunk ports
a trunk port if you remember can support multiple villans with some traffic sent tagged and some traffic
sent untagged across the native land.
So in this example you put the phone in the voice the land and send traffic to it as tagged as a two
to one keyframes the native land would be used to send traffic to the PC untagged so tagged frames are
sent into the phone and untag frames are sent to the PC.
Once again the phone would learn the villain information directly from the switch.
You wouldn't have to configure the phone with the voice Villon they are once again a number of issues
with configuring your network in this way.
The first issue is that this port cannot be configured as a secure port.
Port security can only be enabled and access ports not trunk ports.
Another issue that used to affect Cisco solutions is that in the old days 79 05 phones which were the
low range basic phones often used to reset because of the number of broadcasts received.
The problem with a trunk link is that a trunk by default allows all the lands across it.
So the phone in the scenario would receive broadcasts going to all the lands.
So if a PC on the right hand side here for example was jabbering and was sending many broadcasts those
broadcasts would be received by the phone and have to be processed by the phone.
So in the past phones like the 79 05 which were a basic low entry IP phones reset because they didn't
have the processing power to process all the broadcasts received.
So this caused a lot of issues because your phones would just randomly reset.
So what you had to do in the old days is you had to configure this as a trunk and then manually prune
the trunk to only allow traffic to the voice of the land and the of the land.
Another issue was that on certain switches hoarfrost couldn't be enabled on Concorde's and to make matters
worse a lot of the IP phones would actually copy the tagged frames that they received out of the PC
port and the PC if running a hacking tool and supporting editor one key could receive all of that traffic.
So the PC would have visibility of other villains not just the villain on which it resides.
So this isn't a recommended implementation today but if you come across a really old switch that doesn't
support multivalent exports which we'll discuss in a moment.
You could configure that port as a transport.