# Extensions Extensions are part of **phonegroups** and serve as end points for calls, or where calls can be placed from. **Extensions** are set to use a **[Class of Service](https://public.intellasoft.net/books/cli/page/class-of-service)** to define how calls from this extension are handled. # Adding an Extension 1\) Enter the CLI's configuration mode. 2\) Enter the number of the **Extension** you wish to create. You will be prompted with the minimum required settings. An **extension** does not necessarily need to be a number, but in most this cases this is recommended. ``` servername(config)# extension 5000 servername(config-extension 5000)# ```
Option | Description |
SIP | Physical phone (such as Polycom) or a software phone (such as Linphone or X-lite) |
IAX2 | Inter-Asterisk exchange |
DAHDI | Phone cards physically installed in computers, not commonly used |
VIRTUAL | Used mainly for mailboxes |
SIP-VIRTUAL | Acts as a secondary extension (or tertiary, if using two) for a SIP device, but is still considering a separate extension. |
It is important to remember to use the correct email address. That being said, it is NOT recommended to disable saving the voicemail on the extension itself and only have it sent through email since your voicemail could be lost if there is something wrong outside of the Intellasoft platform (transmission issues, email server (SMTP) issues).
7\) Lastly it is important to set a PIN for the voicemail, so the user of the extension can access their voicemail securely and prevent unwanted access. ``` vbox-markm(config-extension 5000 voicemail)# pin 0011 ```Setting | Description |
all\_call\_forward | Call forwarding |
always\_autoanswer | Whether or not to send an always answer header when calling this extension |
autoanswergroup\_id | |
busy\_call\_forward | If the extension is busy or unava |
call\_screening | |
callerid\_name | Caller ID name |
callerid\_number | Caller ID number |
cos | Class of service when this extension makes a call |
department\_name | |
device\_type | (\*) Protocol that this device will use |
did | Inbound DID (Direct Inward Dialing) |
do | To run exec commands in config mode |
exit | Exit from this level (with notification of incomplete config) |
external\_callerid | What callerid to use when the extension dials out a route |
iax | Change IAX-specific extension settings |
in\_directory | Enable/Disable showing this extension in company directories |
no | Clear settings |
override\_extension | Override the dialable extension |
phone\_type | Extension type |
phonegroup | Phonegroup that this extension is a member of |
phonemake\_id | |
phonemodel\_id | |
polycom | MAC Address of the physical phone this extension is assigned to |
polycom\_reg | Registration number on the physical phone (ie: polycom reg number) |
record | Whether to record all calls to/from this device |
ringseconds\_till\_voicemail | |
show | Show the running-config for the current item |
sip | Change SIP-specific extension settings |
tenant\_name | Tenant that owns this phone |
twinning\_number | Twinning number. Ring an external number such as a cell phone. |
user\_id | |
username | Web portal username that is assigned to this extension (Note: a username can be assigned to more than one extension) |
vmail\_phonegroup\_override | Override what phonegroup this extension's mailbox is a member of |
vmail\_subscribe\_override | Override what mailbox this extension subscribes to |
voicemail | Change voicemail settings |
voicemail\_enable | Enable/disable voicemail for this extension |