Best Practices for Extensions
By doing a little advanced planning on the extensions in your organization you can make your users more reachable and fully exploit the functionality of the OnSIP Hosted PBX.
Extensions should be four digits and start with a 7
You will have the best success with extensions that are four digits long and start with a seven. Many customers have extensions beginning with a "1". The first problem with extensions beginning with a "1" is that they may conflict with your Attendant Menu. For example if, on your Attendant Menu, you have an option to: "Choose 1 for sales, 2 for customers service, etc...", if the caller chooses "1" for sales, we have to wait four seconds to see if they actually wanted 1 just for sales, or they hit '1' on their way to dialing extension '101.'
The second issue is with Polycom phones and other phones that have a digitmap or some kind of internal dial-plan, as soon as you dial the '1' the phone is then expecting you to dial 10 more digits with the next digit being a number between 1 and 9. So, as soon as you dial "10" on your way to dialing "101" the phone will give you a fast-busy.
Extensions that are four digits long give you the flexibility to designate the third digit (the digit in the 'hundred's place') to something specific, e.g. a voicemail box or cell phone.
Extensions for voicemail boxes and Cell phones
In order to send calls directly to a user's voicemail box, that voicemail box must have a direct dial extension. To add an extension to a voicemail box, log into the OnSIP admin portal and choose the 'Resources' tab. Then, choose the 'voice mailboxes' filter (little white box) at the top of the list to see all the voicemail boxes on the system. Give each voicemail box it's own extension.
You can do the same for cell phones. Create a new Resource of type "External Phone Number." Enter the external phone number, be it a cell phone, home phone or other frequently dialed external phone number. Save the number. Once it shows up in the list below, click on the number and assign it an extension.
Examples
For example, if the extension for the user is 7001, you can create an extension for their voicemail box that is 7701. Do the same for all extensions. Then, if you know someone's extension, just by changing the third digit to a '7' you then know the direct transfer extension for their voicemail box.
You can also do this for cell phones. They could maybe be the '9' extension. Then, when finished you could have user Sue Smith be extension 7001 for her phone, 7701 for direct transfer to voicemail and 7901 to send calls to her cell phone.
