Archive for the ‘power’ tag
IIUC Notes – Getting Phones on the LAN
More study notes. Correct if wrong, though I hope I get some of it right since I already since I'm an R&S guy. :$
Switchport Configuration
- switchport mode access: This config makes the port an access port that carries the primary and voice VLAN traffic
- switchport mode trunk: This config akes the port a trunk unconditionally, but it will still send DTP messages
- switchport nonegotiate: This config keeps the port from sending DTP messages.
- switchport mode dynamic auto: If the port receives DTP messages, it will become a trunk. If not, it will be an access port.
- switchport mode dynamic desirable: The port actively sends DTP messages trying to become a trunk. This is the default configuration on a Cisco switch.
Cisco IP Phone Boot Process
- Phone connects to an Ethernet switch and gets power if needed
- Switch tells the phone the correct voice VLAN through CDP
- Phone sends DHCP request for its voice VLAN
- DHCP offer includes the TFTP server from which to download the config
- Phone downloads the config from the TFTP server
- Phone contacts the call processing server as dictated in the config file
DHCP Settings on a Cisco Router or L3 Switch
R1(config)#ip dhcp pool MYPOOL
R1(dhcp-config)#network 192.168.0.0 255.255.255.0
R1(dhcp-config)#default-router 192.168.0.1
R1(dhcp-config)#dns-server 192.168.0.10
R1(dhcp-config)#option 150 ip 192.168.0.20 <– Tells the phone to download the config from this TFTP server
R1(dhcp-config)#exit
R1(config)#ip dhcp excluded-address 192.168.0.1 192.168.0.100 <– Don't use these IPs when handing out DHCP
NTP
Why should you use NTP for a CME setup?
- Phones display correct time
- Voicemails have the correct time
- CDRs are timestamped accurately
- Router logs are timestamped accurately
- Time-based access worked predictably
R1(config)#ntp server 1.1.1.1
R1(config)#clock timezone MYTZ -5 <– Sets the timezone to a zone called MYTZ that's 5 hours behind UTC
IIUC Notes – Assigning Ephone-dns to Ephone Buttons
These are some of my notes on my IIUC studies. Since I am a novice as voice stuff, please let me know what I get wrong.
An ephone is a representation of a phone. It's basically a structure of features that a phone will have.
Configuration in CME:
R1(config)#ephone 34 <– This is just a tag and has nothing to do with an extension or phone
R1(config-ephone)#mac-address 1111.2222.3333 <– Assigns this ephone to the phone with that MAC address
An ephone-dn is a directory number that can be assigned to one or more phone. This is usually your extension and/or DID number.
Configuration in CME:
R1(config)#ephone-dn 18 <– Again, just a tag
R1(config-ephone-dn)#number 1000 <– the extension
Ephone-dns (i.e., extensions) are assigned to ephones through the button directive under the ephone setup. You can have more than one assignment per button command.
Configuration in CME:
R1(config)#ephone 34
R1(config-ephone)#button 1:18 <– Assigns extension 1000 (through ephone-dn 18) to button 1
The colon (:) in the button line is a separator that means that this is a normal ring phone – when someone dials that extension, your phone rings and lights up. There are other separator characters.
| Character | Function |
| : | Normal ring; the phone rings and lights up |
| b | Call waiting beep; the phone will light up, but there will be no ring. If you're on the line, you'll hear a beep on the line. |
| f | Feature ring; a triple ring |
| m | Monitor mode; lets you see the status of the line without being able to use it. Think of receptionists seeing if the boss is on the phone. |
| o | Overlay line without call waiting |
| c | Overlay line with call waiting |
| x | Overlay expansion with rollover |
| s | Silent; disable ringing and call waiting beep, but lights still flash |
| w | Watch mode; like monitor, except it monitors if any line on the phone being watched is active. If I have 4 ephone-dns on my phone and am on line 2, if you're watching line 1 of my phone, you'll see it as active |
Configuration in CME:
R1(config)#ephone 34
R1(config-ephone)#button 3m15 <– Monitors ephone-dn on button 3
R1(config-ephone)#button 4s82 <– Assigns ephone-dn 82 to button 4 but nothing will ring
R1(config-ephone)#button 5f31 <– Assigns ephone-dn 31 to button 5 with a triple ring
IIUC Notes – Powering Cisco Phones
Feel free to correct anything that is wrong or incomplete.
- Power over Ethernet (PoE)
- Can provide power to a Cisco phone, access point, security camera, etc., through the network cabling, eliminating the need to plug the phone into the wall for power.
- Generic term for providing power on the Ethernet cable
- Provides centralized power that can be put on a UPS
- Allows devices to be located away from power outlets
- Removes cabling clutter at the user's desk
- Can be provided through PoE-enabled switches, power panels or inline couplers (power injectors)
- Oversubscription is common
- If every device on a switch asks for full power, the switch may not be able to handle the load.
- Of course, devices can be powered with a power brick at the desk
- 802.3af
- IEEE standard for PoE from 2003
- Defines power classes so different devices can ask for different power levels
- Class 0: 15.4W allocated
- Used for el cheapo devices that just want power
- Class 1: 4.0W
- Class 2: 7.0W
- Class 3: 15.4W
- Class 0: 15.4W allocated
- Uses all 4 pairs of wire, so works on gig links
- Power procedure
- Small DC current is applied to the line
- If an 802.3af device is attached, it runs the current through a resistor
- The resistance is detected by the switch which can determine the class of power
- Power is applied to the device
- Cisco Inline Power
- Cisco's version of PoE created in 2000 (before 802.3af)
- Each device tells the switch what its power needs are
- Power procedure
- PoE device connected to the switch
- Switch sends Fast Link Pulse (FLP)
- If FLP is received back, 6.3W of power are applied
- Device boots off of 6.3W and tells the switch what its real power requirements are via CDP