By default, network routers handle traffic on a first-come, first-served basis. Fixed delays cannot be controlled as they are caused by the physical distance the packets travel. They are especially problematic when satellite circuits are involved because of the long distance to a geostationary satellite and back; delays of 400–600 ms are typical. Latency can be minimized by marking voice packets as being delay-sensitive with QoS methods such as DiffServ.[16]
Other basic features to consider include the phone itself should your provider offer its own handsets. Many residential providers don't since their bridge devices allow them to work with old-style landline phones, but some, especially the larger and more business-oriented players, do offer special VoIP phones. These look and work the same as a regular phone aside from the initial setup process, which will require making sure the phone is connected to your Internet router in some way and then configured to access the VoIP provider's service from there.
To get a better picture of the savings of VoIP for home use, here's a real life example: Long distance calls with a VoIP provider can be as little as $10 per month, if not less. Major telecommunications corporations typically charge more for such packages, even 2 or 3 times as much. If you look at this over the course of a year, that’s no small change.  
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.
Another legal issue that the US Congress is debating concerns changes to the Foreign Intelligence Surveillance Act. The issue in question is calls between Americans and foreigners. The National Security Agency (NSA) is not authorized to tap Americans' conversations without a warrant—but the Internet, and specifically VoIP does not draw as clear a line to the location of a caller or a call's recipient as the traditional phone system does. As VoIP's low cost and flexibility convinces more and more organizations to adopt the technology, the surveillance for law enforcement agencies becomes more difficult. VoIP technology has also increased Federal security concerns because VoIP and similar technologies have made it more difficult for the government to determine where a target is physically located when communications are being intercepted, and that creates a whole set of new legal challenges.[68]
Be aware, however, that there are significant security implications regarding the use of mobile softphones on employee-owned devices. While it's possible for your employees to simply download the appropriate software from their respective app store, your IT department should be involved with allowing access while also confirming that necessary security steps are taken. Also be aware that there are important reasons not to allow soft phone installations on private devices of any type because you may not be able to remove that phone client if the employee leaves the company, and because local laws may impact how much control you have over the use of the device.

The majority of plans are loaded with a great selection of features that can come in handy when you are making or receiving calls. Many providers offer over 30 features included in the low monthly fees. These include basic call management features such as call waiting, call forwarding, call blocking, caller ID name, do not disturb, and voicemail. More advanced features such as the voicemail to email feature let's you access your messages at anytime, even when you are away from your home, simply by checking your email inbox. Distinctive ringing, additional virtual numbers, and Smartphone Calling App's are other examples of more advanced features that can be useful.