How to Choose a VoIP Solution That Match Your Personal or Office Need

VoIP phones or IP phones are telephones which uses Voice over Internet Protocol technologies allowing telephone calls to be made over an IP network instead of the ordinary PSTN system. VoIP phones may have many features an analog phone doesn't support, i.e e-mail-like IDs for contacts that may be easier to remember than names or phone numbers. VoIP phones calls can traverse the Internet, or a private IP Network such as that of a company LAN (Local Area Network).

Alongside with its advantages, VoIP phones have some disadvantages:

• VoIP phones requires internet connection to make calls outside the Local Area Network, unless a compatible local PBX is available to handle calls to and from outside lines.
• VoIP Phones and the routers they connect through usually depend on main electricity, unlike PSTN phones which are supplied with power from the telephone exchange.
• Poorer voice quality or even the call to be dropped completely may happen, caused by particularly residential internet connections that are easily congested.
• Like other network devices, VoIP phones can be subjected to Denial of Service (DoS) attacks as well as other attacks especially if the device is given a public IP address.
• VoIP phones may do not work as well on satellite internet and other high-latency internet connections due to the latency induced by protocol overhead.

VoIP phones device may come as a simple, software-based Softphones, or in a form of purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone. There's also the possibility to reuse ordinary PSTN phones as VoIP phones, using additional device called Analog Telephony Adapters (ATA).

VoIP phones may have different methods of connection and protocols:

1. VoIP phones with dialup modem connections
2. VoIP phones with Ethernet connections
3. VoIP phones with Wi-Fi / 802.11 connections
4. Software VoIP phones

Control protocols used by VoIP phones may vary from Session Initiation Protocol, Skinny Client Control Protocol, to proprietary protocols like that used by Skype.

How to choose a VoIP phone that match your personal or office need?

1. Determine your choice between a hardware VoIP phone or a software VoIP phone.

Hardware VoIP Phone

Hardware VoIP phones may look like a common PSTN telephone or mobile phone. A hardware VoIP phone has standard hardware components including speaker and microphone, key pad, LCD display, general purpose processor (GPP) to process application messages, a voice engine or a Digital signal processor to process RTP messages, ADC and DAC converters to convert voice to digital data and vice versa, ethernet or wireless network hardware to send and receive messages on data network, and power source (battery, DC source, or electricity power over ethernet). Some VoIP phones may also support PSTN phone lines directly.

Hardware VoIP phones are generally easier to use and do not require a PC. If you select a hardware VoIP phone, consider these features:

- Which connection(s) is supported by the VoIP phone: Ethernet, Wi-Fi, Dial up, or ISDN?
- Is it IPv6 support?
- Is it has videoconferencing support?
- Handset type: Corded or cordless?
- Telephone form: Handset or a headset?
- Does it have a speakerphone?
- Does it have good ergonomics?

Software VoIP Phone

Software VoIP phone, as it name suggest, simply turn your PC into a VoIP telephone. If you already own a personal computer, software VoIP phones usually less expensive than hardware phone, and may offer better options for CTI (Computer Telephony Integration) than Hardware VoIP phones.

If you select a software VoIP phone (softphone), consider these features:

- Does the software compatible with your computer's operating system?
- Does the software support video conferencing?
- Does the software support shared whiteboarding?
- Is the software easy to use?

2. For both types (hardware and software VoIP phones) consider supports to these common features:

- Caller ID
- Dialing using name/ID: user doesn't need to save a number to a sip phone.
- Encryption support, including Secure RTP and AES
- Conference and multiparty call
- Do-Not-Disturb (DND) support
- Custom ringtones support
- Call transfer and call hold
- STUN support
- Symmetric RTP support
- Locally stored and network-based directories
- SIP outbound proxy support
- QoS support
- VoIP call control protocols support: H.323, SIP, MGCP, IAX2
- VoIP codecs support, including support for G.711, G.722, G.723, G.726, G.727, G.728, G.729, ILBC, Speex, GSM - Full Rate, GSM - Enhanced Full Rate, GSM - Half Rate, and DoS FS-1015 VoIP codecs.
- Additional applications like weather report, attendance in school and offices, Live news etc.