Configuring Phones in Packet Tracer

** The commands are written for you to copy into a text editor. The words in all caps are the parameters that you need to fill in with the required info. After you edit the required parameters, copy the commands into the CLI of the device you're working on. **

The only network device I've found capable of making the phones work on your network in packet tracer is the 2811 Router. It's the only device that can run the "telephony-service" command which is needed to configure the phone lines on the network.

In the router, configure a DHCP pool for the phones. For phones, the default-router address should be the address of the port on the router connecting to the network that the phone is on. If you are getting DHCP Conflict messages, exclude the address of the default gateway.

conf t
ip dhcp pool NAMEOFPOOL
network IPADDRESS SUBNET
default-router IPADDRESS
option 150 ip DEFAULTROUTERIPADDRESS
exit
ip dhcp excluded-address DEFAULTROUTERIPADDRESS

Configure Telephony Service on the router. Max ephones and dn can be any number of phones the software will allow.

telephony-service
max-ephones 5
max-dn 5
ip source-address DEFAULTROUTERIPADDRESS port 2000
auto assign 4 to 6
auto assign 1 to 5
exit

Configure phone lines.

ephone-dn 1
number XXXXX
ephone-dn 2
number XXXXX

Rinse and repeat for all the phones lines you want.

The only way I've gotten this to work in packet tracer is with the switch configured as a layer 2 switch, with a trunk line connecting the router. On the router you'd then have to configure a sub-interface for the VLAN the phones are on.

Here's how to configure the link to the from the switch to the router.

int INTERFACENUMBER
switchport mode trunk

Here's how to configure the link from the router to the switch

int INTERFACENUMBER.SUBINTERFACENUMBER
encapsulation dot1q VLANNUMBER
ip address IPADDRESS SUBNETMASK

How to configure the link to the phone

int vlan VLANNUMBER
ip address IPADDRESSOFVLANINTERFACE SUBNETMASK
ip helper-address DHCPSERVERIPADDRESS
int INTERFACENUMBER
switchport voice vlan VLANNUMBER

If you have a PC attached to the phone, you must add a seperate VLAN number for the PC data.

int vlan VLANNUMBER
ip address IPADDRESSOFVLANINTERFACE SUBNETMASK
int INTERFACENNUMBER
switchport access vlan VLANNUMBER