In addition to making sure your internet service can handle your VoIP traffic, you also need to make sure your local area network (LAN) can handle it. What makes network management tricky with VoIP is that if you simply drop it onto your network, that traffic will get processed the same as any other traffic, meaning your shared accounting application or those 20 gigabytes worth of files your assistant just moved to the cloud.
Most people screen their phone calls and often avoid answering unknown numbers. If you’re applying for new positions, you should try to view each unexpected call as an exciting opportunity! In the event that you simply can’t pick up the phone, you’ll want a polished voicemail greeting to let the caller know they’ve reached the right person.

If your voicemail is still full, move on to the next step. Wireless carrier’s voicemail system. Even though you deleted all your voicemails from the Phone app, your iPhone may still say voicemail is full. When someone leaves you a voicemail, it’s stored directly in your cell phone carrier server.
Using an on-site PBX means you own the hardware of your phone system. You can modify the system to you exacting specifications, including changing phone numbers and adding extensions as necessary. You will also be in charge of ensuring the security of your data stores such as phone number listings and voicemail recordings.