VoIP has drastically reduced the cost of communication by sharing network infrastructure between data and voice.[48][49] A single broad-band connection has the ability to transmit more than one telephone call. Secure calls using standardized protocols, such as Secure Real-time Transport Protocol, as most of the facilities of creating a secure telephone connection over traditional phone lines, such as digitizing and digital transmission, are already in place with VoIP. It is necessary only to encrypt and authenticate the existing data stream. Automated software, such as a virtual PBX, may eliminate the need of personnel to greet and switch incoming calls.
Before you can start considering a phone system, you need to figure out what it's going to be used for, and how much of your business will be involved. You need to look at your existing phone system and decide whether you're going to simply keep all of it and bolt some VoIP functionality on top, retain only part of it, or replace the whole thing. Frequently, a total replacement isn't in the cards if only because some parts of your existing phone system can't be easily changed over to softphones or even desktop VoIP phones. For example, if you have a heavy manufacturing environment with outdoor activities, such as a steel fabrication yard or even a landscaping company, your old outdoor phones may be exactly what you need. You also need to decide what features of the existing phone system are required, and what features of a future phone system you feel are necessary to carry into the future.
In the United Arab Emirates (UAE), it is illegal to provide or use unauthorized VoIP services, to the extent that web sites of unlicensed VoIP providers have been blocked. However, some VoIPs such as Skype were allowed.[56] In January 2018, internet service providers in UAE blocked all VoIP apps, including Skype, but permitting only 2 "government-approved" VoIP apps (C’ME and BOTIM) for a fixed rate of Dh52.50 a month for use on mobile devices, and Dh105 a month to use over a computer connected."[57][58] In opposition, a petition on Change.org garnered over 5000 signatures, in response to which the website was blocked in UAE.[59]

(e) In India no Separate Numbering Scheme is provided to the Internet Telephony. Presently the 10 digit Numbering allocation based on E.164 is permitted to the Fixed Telephony, GSM, CDMA wireless service. For Internet Telephony the numbering scheme shall only conform to IP addressing Scheme of Internet Assigned Numbers Authority (IANA). Translation of E.164 number / private number to IP address allotted to any device and vice versa, by ISP to show compliance with IANA numbering scheme is not permitted.
That covers VoIP basics, but what about the more advanced options, and why is VoIP able to offer more advanced features where a regular phone can/t? Again, the secret is software. A VoIP system, whether home or business, can access a much richer software layer than a standard line from the plain old telephone service (POTS). On the business side, this flexibility has extended to integrating VoIP with other forms of communication to such a degree they all become a single platform, generally called Unified Communications as a Service (UCaaS). You won't anything that sophisticated when you're shopping for residential service, however.
However, you may also want features like on-hold music, call queues, voicemail to email translation, and automatic answering and forwarding of calls. If all of the employees are working out of the office, you can use the automatic attendant to determine which employee should receive the call. The attendant then can route the call to that employee’s mobile phone.
VoIP service simply enables your phone calls to be transmitted and received over your home Internet connection instead of your telephone landline. This is perhaps why some people refer to the service as being an Internet phone service or broadband phone service. This does mean though that you need a high speed Internet service to be able to use VoIP for your phone service.