Fortunately, there are several dedicated residential VoIP providers who offer nationwide service, usually with worldwide calling plans. With one of these you should be offered at least four core features. Those include caller ID, voicemail hosted by the provider (meaning you don't need an answering machine), call waiting (essentially a one-line hold), 911 support (sometimes called "E911"), and three-way calling allowing you to reach out to a third participant in any phone conversation. There will likely be a slew of other features available, but they'll differ across quality providers while these four should always be available. Most of these will work in a two-step process:
VoIP calling as your home phone service is the best way to consolidate calling and networking in one convenient place, while saving a lot of money. Landlines are limited, and serve no more function than dialing out and receiving calls. Setting up your VoIP phone to forward calls to your mobile number is just one of the many ways you can stay connected, even when you’re not home. A common concern in making the transition to VoIP is that giving up your landline service will ultimately mean giving up your number in exchange for a new one. With number portability, residential VoIP providers allow you to keep your old landline number and assimilate it into your new phone service. Check with your VoIP provider to see if your particular number is eligible for porting, as they are portable in most cases.

The growth of VoIP today can be compared to that of the Internet in the early 90’s. The public is getting more and more conscious of the advantages they can reap from VoIP at home or in their businesses. VoIP which not only gives facilities and allows people to save​ but also generating huge income for those who ventured early into the new phenomenon.
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 stored in the cloud.
The quality of voice transmission is characterized by several metrics that may be monitored by network elements and by the user agent hardware or software. Such metrics include network packet loss, packet jitter, packet latency (delay), post-dial delay, and echo. The metrics are determined by VoIP performance testing and monitoring.[20][21][22][23][24][25]
BYOD stands for bring your own device. This term refers to employees conducting company business on personal laptops, tablets, and phones instead of on company-owned gear. Most VoIP companies offer BYOD features and solutions within their plans, either included or at additional cost. However, extra IT security layers and company guidelines for BYOD are on you.
With integration being at the heart of VoIP and UCaaS, you can't make a purchasing decision here without thinking about the future. On one side, think about what you'll need in 1-5 years. On the other side, consider each vendor carefully to see what they've done over the last half decade in terms of product development and keeping up with VoIP and UCaaS trends.
Ooma advertises only two plans: Ooma Office and Ooma Office Pro. Ooma Office includes unlimited domestic calls, three-way calling, virtual fax machines, plus most of the industry-standard features you’d expect from a leading private branch exchange (PBX) provider. Meanwhile, Ooma Office Pro offers more premium features, including call recording and enhanced call blocking—to name a few. But with either plan, you’ll have to pay a $29.95 one-time activation fee to get your service started. straddles the line between business and residential VoIP with a bunch of pricing plans suited to families. It structures its packages a little differently than its competitors. Customers can choose between pay-per-minute plans, which are cheaper but have fewer functions, or unlimited plans, which are more expensive but all-inclusive. The pay-per-minute plans come with a 30-day money back guarantee.
Softphones are increasing in importance in VoIP offerings to the point that for some they're the only choice. They are a critical part of UCaaS and are as common on mobile phones and tablets as they are on desktop PCs. For workers in call centers, softphones are a common tool because of they're the front-end window of any CRM or help desk integration. So, for example, a softphone can combine a telephone conversation with text chat and screen sharing, which means a conversation between two employees can seamlessly add more participants, handle private text chats between those participants while the call is still going on, and extend to a collaboration session in which the group shares screens, documents, and data—no prep, no reserved lines, just button clicks.  
An IP phone or VoIP Adapter (ATA) – You’ll see a wide range of prices between the different providers when it comes to equipment. Some providers have expensive equipment and “freemium” service; others will lease you equipment for free and charge more per month. Between those two, you have a lot of in-between. An IP phone plugs directly into your modem or router, and an ATA lets you use a legacy phone over the VoIP network. You need an IP phone to truly enjoy all the benefits of VoIP calling, which is why VoIP phones are becoming more popular.

Network routers on high volume traffic links may introduce latency that exceeds permissible thresholds for VoIP. Excessive load on a link can cause congestion and associated queueing delays and packet loss. This signals a transport protocol like TCP to reduce its transmission rate to alleviate the congestion. But VoIP usually uses UDP not TCP because recovering from congestion through retransmission usually entails too much latency.[16] So QoS mechanisms can avoid the undesirable loss of VoIP packets by immediately transmitting them ahead of any queued bulk traffic on the same link, even when the link is congested by bulk traffic.
A critical part of the discussion with your IT staff will be whether your existing data network can handle the extra load that will be placed on it by the new phone system. You'll need a network that can handle more advanced network management capabilities, including tools to fight jitter and latency as well as to provide Quality of Service (QoS) and different kinds of network segmentation, especially virtual LANs (VLANs). Only tools like these can help free up your network from too much congestion, which can cause your call quality to decrease or even crash the VoIP system entirely.  
Unless you’re running a major business out of your house, chances are you won’t need or be interested in the ability to do video conferencing with dozens of people at the same time. The same goes for an auto attendant and business software integrations. First decide which features are priorities for you (unlimited calling, voicemail-to-email, international calling plans, etc.) and then take a look at what each company offers. After all, there’s no sense in paying for features that you don’t need. 
To help businesses work from home, RingCentral provides unlimited internet faxing and audioconferencing on all the plans listed above. Video meetings can include up to 100 participants, and meetings can last up to 24 hours—just in case your group needs to burn the midnight oil. Standard plans and higher also include popular communication integrations like 365, G Suite, and Slack.
Still the pandemic won't last forever so keeping in mind core VoIP criteria is important, too. That means providing voice communications for employees at their desks. VoIP systems may also need to support a call center for sales, customer service, and support; and they often need to connect with and through a host of other communications channels, such as fax machines, video conferencing, conference calling, mobile communications, wireless handsets, and text messaging. On top of that, they're often expected to provide more advanced functionality through software, like shared meeting collaboration, voicemail to email transcription, and call recording. And lest we forget, many businesses still need a service that will connect to public switched telephone network (PSTN).  
Voicemail routing can take multiple forms, but they're basically rules you can apply to incoming calls that will automatically route them to voicemail without even causing a ring. For example, if calls come in with Caller ID blocked, those can be routed directly to voicemail. Or if you're simply not into talking to anyone, you can hang out a digital Do Not Disturb sign and route all calls to voicemail, perhaps until you're feeling more social or every day between the hours of 9 PM and 7 AM. 
It's also critical that you consider the impact of mergers and acquisitions on your phone system, both from your own organization's perspective as well as your VoIP provider. Because VoIP systems turn calls into data, the whole process isn't as plug-and-play standards-based as the old-fashioned analog phone system might have been. Should your company merge with or purchase another, VoIP compatibility will become another significant IT issue.
That situation is for fairly pristine network and business conditions, however. Companies with legacy equipment or unique business needs may need a hybrid PBX, in which a portion of the voice network remains in the analog world, while the rest is converted to cloud-based VoIP. This could happen if you occupy an older building without the necessary Ethernet infrastructure to support VoIP or if you had custom software built a long time ago that simply isn't compatible with newer phone technologies.
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]
Throughout the developing world, particularly in countries where regulation is weak or captured by the dominant operator, restrictions on the use of VoIP are often imposed, including in Panama where VoIP is taxed, Guyana where VoIP is prohibited.[51] In Ethiopia, where the government is nationalising telecommunication service, it is a criminal offence to offer services using VoIP. The country has installed firewalls to prevent international calls being made using VoIP. These measures were taken after the popularity of VoIP reduced the income generated by the state owned telecommunication company.
The receiver must resequence IP packets that arrive out of order and recover gracefully when packets arrive too late or not at all. Packet delay variation results from changes in queuing delay along a given network path due to competition from other users for the same transmission links. VoIP receivers accommodate this variation by storing incoming packets briefly in a playout buffer, deliberately increasing latency to improve the chance that each packet will be on hand when it is time for the voice engine to play it. The added delay is thus a compromise between excessive latency and excessive dropout, i.e. momentary audio interruptions.

If you are seeking a superb pan/tilt/zoom (PTZ) video conferencing camera for medium-size meeting rooms, the Yealink VCC20 is an ideal choice. 2.18M pixels HD CMOS sensor plus 12X optical zoom power the VCC20 HD PTZ, delivering HD images up to 1080p at 30 fps. The Yealink VCC20 camera is an optimal solution for a smaller business environments. It is so detailed and true to life that you feel like you are in the meeting room with everyone else.
Signaling – Performing registration (advertising one's presence and contact information) and discovery (locating someone and obtaining their contact information), dialing (including reporting call progress), negotiating capabilities, and call control (such as hold, mute, transfer/forwarding, dialing DTMF keys during a call [e.g. to interact with an automated attendant or IVR], etc.).

The Yealink EXP50 Color-screen Expansion Module is an ideal solution for receptionists, administrative assistants and contact center workers and give you the ability to monitor contacts and manage a large volume of calls with ease. The Yealink EXP50 Color-Screen Expansion Module for Yealink T5 Series IP phones, including SIP-T56A/T54S/T52S, is designed to expand the functional capability of your SIP phone to a whole new level. It features a large 4.3-inch color-screen LCD, giving you a vivid visual experience. In addition, it provides you with a simple user interface and advanced call handling capabilities. For example, three pages of 20 flexible button shown on the display can be programmed for up to 60 various features.

While it doesn't offer as many features as its business-class version, residential VoIP is still overwhelmingly attractive when compared to standard phone service; firstly because of its much lower overall price tag and second because it simply offers more features than an old fashioned long line. You can keep your current number, suffer zero restrictions when it comes to 911 or long-distance calling, drop your monthly price to a low fixed number, and take advantage of VoIP-only features like smart call routing, virtual numbers, and more.

While we think Grasshopper is great for small businesses, it misses out on our “Best Small-Business Phone Service” title because, compared to Ooma, Grasshopper is a little expensive. Grasshopper plans start at $26 per month, assuming you sign up for annual billing. And starting plans include only one business phone number with up to three extensions.
Mobile clients are softphones optimized for a particular mobile OS and for being used in mobile situations. This means they're designed to switch easily between different cell and wireless connections on the fly. This means you can let your employees use whatever the cheapest wireless connection around them happens to be—and often that can be free. They also let your employees use your company's phone system on their own devices.
While it doesn't offer as many features as its business-class version, residential VoIP is still overwhelmingly attractive when compared to standard phone service; firstly because of its much lower overall price tag and second because it simply offers more features than an old fashioned long line. You can keep your current number, suffer zero restrictions when it comes to 911 or long-distance calling, drop your monthly price to a low fixed number, and take advantage of VoIP-only features like smart call routing, virtual numbers, and more.
Verizon is a household name when it comes to all things calling, and its residential VoIP services don’t disappoint. You can get both unlimited or per-minute calling plans from this communications solution giant. Verizon uses advanced fiber-optic networks to deliver the most crystal-clear sound quality too. So, you’re never struggling to hear and understand what someone on the other line is saying to you.
IP Phones and VoIP telephone adapters connect to routers or cable modems which typically depend on the availability of mains electricity or locally generated power.[37] Some VoIP service providers use customer premises equipment (e.g., cablemodems) with battery-backed power supplies to assure uninterrupted service for up to several hours in case of local power failures. Such battery-backed devices typically are designed for use with analog handsets.
It is much cheaper than a regular landline - most providers offer unlimited calling plans (including long distance) in the USA and Canada for under $10 per month. There are also some great promotional deals available such as 2 year specials that cost around $6 per month (includes all your calling). Comparing this to a regular PSTN (landline) phone service that can cost in the region of $60 per month can result in savings of over $500 per year for many home phone users. If you also regularly call International numbers you can save even more, with rates typically starting from around 1 to 2 cents per minute to many countries.