Government and military organizations use various security measures to protect VoIP traffic, such as voice over secure IP (VoSIP), secure voice over IP (SVoIP), and secure voice over secure IP (SVoSIP).[39] The distinction lies in whether encryption is applied in the telephone endpoint or in the network.[40] Secure voice over secure IP may be implemented by encrypting the media with protocols such as SRTP and ZRTP. Secure voice over IP uses Type 1 encryption on a classified network, such as SIPRNet.[41][42][43][44] Public Secure VoIP is also available with free GNU software and in many popular commercial VoIP programs via libraries, such as ZRTP.[45]
On the physical side, you'll also need to plan for providing Ethernet drops to any new desktop phones you'll be placing on user desks, or even adding capacity to your Wi-Fi network should you decide to use wireless calling. For many organizations a separate network is often winds up being the preferred solution. If that's what happens in your case, you'll need a separate VoIP gateway. You'll also need security that understands voice protocols, and you'll need to have switches and routers that understand VoIP, too. By the time you've covered all those bases, a separate network is often the more effective solution rather than attempting to not only install but also integrate that much new equipment into an existing LAN.
On the higher end of this space, hosted PBX providers, such as RingCentral Office, will generally offer (sometimes even require) on-premises handset hardware, like desk or cordless VoIP phones that get sent to you pre-configured to work with their service. Plug the phones in, make sure they see an internet connection, and after some self-configuration time, your VoIP service goes live auto-magically.
VoIP is a relatively new technology and it has already achieved wide acceptance and use. There is still a lot to improve and it is expected to have major technological advances in VoIP in the future. It has so far proved to be a good candidate for replacing the POTS (Plain Old Telephone System). It, of course, has drawbacks along with the numerous advantages it brings; and its increasing use worldwide is creating new considerations surrounding its regulations and security.
Designed for busy executives and professionals, Yealink SIP-T52S is an easy-to-use Media IP Phone with a 2.8-inch color-screen and a distinctive appearance and structure. For its simplified and user-friendly design as well as user interface, it brings the IP phone and users closer to an unparalleled operating experience. With Yealink Optima HD voice technology, T52S enhances its audio quality, adding Opus audio codec delivering superb audio and voice communications.
Such emergency services are provided by VoIP vendors in the United States by a system called Enhanced 911 (E911), based on the Wireless Communications and Public Safety Act of 1999. The VoIP E911 emergency-calling system associates a physical address with the calling party's telephone number. All VoIP providers that provide access to the public switched telephone network are required to implement E911,[34] a service for which the subscriber may be charged. "VoIP providers may not allow customers to "opt-out" of 911 service."[34]
VoIP stands for Voice over Internet Protocol. It is also referred to as IP Telephony, Internet Telephony, and Internet Calling. It is an alternative way of making phone calls that can be very cheap or completely free. The ‘phone’ part is not always present anymore, as you can communicate without a telephone set. VoIP has been named the most successful technology of the last decade. 
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.