Need help determining extension length - 3 or 4 digits

[stever]

I have been experimenting with 3CX for several months. I have been thinking that 3 digit extensions would be best for us BUT since I can't easily change this once we go live, I want to make sure I am not missing something. (I am sure there is!)

We have 4 locations and will have one on premise 3CX PBX. Users will potentially move from one location to another to cover for vacations, etc. so keeping a different series of extensions for each location is not necessary or feasible. We have approx. 80 employees with around 65 of these needing extensions. I do not anticipate much growth in the next 5 years. Definitely should be below 100 total employees and maybe 75 needing user extensions. Our current phone system has 3 digit extensions. It seems like with 3CX there is a need for more extensions that are used for "making" things work or for additional features. I have had one communications company recommend 5 digit extensions but had another competent one say that we would be fine with 3 digit ones. If I were consulting a client on this, it would be less risky to recommend 4 digits 3 digits. On the other hand, I would not be the one that is around the employees on a daily basis hearing them complain about the new phone system... I am trying to make the transition as seamless as possible, which keeping the same extension length (and therefore numbers) would be one small thing that would help.

Loc 1 - 50 Users + 10 conference type phones
Loc 2 - 10 Users + 4 conference type phones
Loc 3 - 3 Users
Loc 4 - 3 Users

Here is my planning so far:
001 - 099 Dummy Extensions
100 - 110 SP Parking shortcut
111 - 199
200 - 299 Employee Extensions (use same as current ones)
300 - 349 Conference phones and other phones
350 - 399
400 - 499 Cell phone direct extensions
500 - 599
600 - 699 Personal IVR's for extensions
700 - 799
800 - 849 Ring Groups/ Queues
850 - 880 Paging groups
881 - 899
900 - 999

Any opinions or thoughts would be appreciated.

Thanks,
Steve

 

[sbowers]

First off, sorry about the lengthy post. I have had some experience with this and wanted to share my thoughts. When I configure systems for other businesses with multiple locations I prefer to keep the mapping of the numbers separate for each location. Based on the information that you provided I would make it 4 digits, mainly for simplicity when it comes to managing extensions/troubleshooting. I would keep your HQ at 1000, Second Local 2000, 3rd 3000 and 4th 4000. This is how I managed my customers who have more than 2 locations. I know you mentioned that keeping extension numbers separate for each location isn't necessary. I prefer this method for two reasons, it leaves managing extensions easier since you'll know which location the extension is location and additionally since you know where that location is located it makes diagnosing any networking issues a lot easier and quicker to resolve. Plus it looks cleaner in the management console. You can keep it at 3 digits if you'd like. There is nothing wrong with that.

Given your situation it isn't necessary to have multiple extensions for a user who may travel to a different location. What I do in situations like this, is where ever that user is based out of the most, that is the extension mapping that I give them. When they are at the other facility their extension goes with them. This way people wont have to remember multiple extensions for one user. Either I set up multiple users on one phone, or if they have a laptop that they take with them I get them a Bluetooth headset or wireless headset, pending on the capability of the PC, and have them use the soft-phone feature on the client so that their PC becomes the phone. This cuts down on cost as you wont have to purchase more phones, just install the client or add another user on an existing IP phone.

Hope this helps. Let me know if you need clarification or any other questions.

 

[leejor]

I would go with 4 digits. It means users have to dial an extra digit, but, gives you flexibility in the future if things change, and they probably will. The fact that you are asking the question, means you have your doubts about going with only 3 digits.

 

[stever]

Thanks Sam and leejor. Are there uses for additional extensions that I am not thinking of? For instance I was keeping 100 extensions for direct dial to cell phones. I realize that growth could screw me with 3 digit extensions but I was wondering what uses/need of extensions that I hadn't thought about.

 

[leejor]

Speed dial?
https://www.3cx.com/blog/voip-howto/speed-dials-using-3cx-outbound-rules/

 

[stever]

leejor, It looks like you can use 4 digit speed dials even if your extensions are 3 digits.

Steve

 

[stever]

sbowers, thanks for the lengthy reply. It helps me think through things. When you set two users up on one phone, is there a way to easily disable the temporary user's extension without deleting it so that it is there the next time that they are filling in?

Steve