There's a lot of discussion about the merits of different Voice over IP services, but choosing a service provider isn't the only decision you'll need to make once your company takes the plunge to deploy VoIP; it helps to have a working knowledge of the hardware devices involved in transmitting voice calls over an IP network, and an idea of what different components do and which ones you need.
Soft phonesSome VoIP services are software based. That means, at the user's end, the only hardware device needed is a computer with an Internet connection. The computer requires the appropriate audio equipment: a sound card with speakers or earphones to hear the other party's transmissions, and a microphone to input your own side of the conversation.
A soft phone is the industry name for a software program that users can install on a PC to make IP phone calls; most free soft phone services handle only PC-to-PC calls. Users typically pay a monthly or per-call fee for public switched telephone network (PSTN) gateway services to allow them to place calls from their soft phones to regular landlines and cell phones. Perhaps the best known soft phone software is Skype.
Some examples of business-oriented soft phone software are:
- 3CX VoIP Phone for Windows. This is a Session Initiation Protocol (SIP)-based product available in both free and enterprise editions. It works with providers such as Asterisk and Sipgate.
- ArrowPhone. Another Windows software-based phone, this one for H.323 networks. Customers can use the ArrowPhone over VPN networks behind a firewall. A free demo version is available for download.
- AGEphone. Uses a "microSIP" stack and runs not only on Windows but also on CE/Pocket PC and Windows Mobile, with Linux and Symbian versions planned for the future. Has web-based interface that allows users to make and receive calls through a web page.
- E-Phone. Free IAX2 soft phone for Windows.
- Gizmo. Free soft phone for Windows, Macintosh OS X, and Linux.
- SIP Communicator. Java-based open source VoIP client that supports both audio and video sessions over both IPv4 and IPv6.
Hardware for soft phones
One big drawback of soft phones is the physical interface.
Although some users prefer the headset or microphone/computer speaker setup,
others are uncomfortable with it and want to be able to talk on a "real" phone.
USB handsets can give soft phone users the familiar telephony experience along
with the improved voice quality of PC-based VoIP communications. Soft phones
plug into the computer's USB port.
USB phones come in many styles, including handsets, desksets with speaker phones, and base station/cordless models. Some USB phone sets require driver software, so it's important to be sure there are drivers available for the operating system(s) on which a user runs the soft phone software. USB phone sets are available from Yuxin, World Phone, and Eutectics. (Note that USB phones are different from IP phones, which do not have to connect to a PC.)
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dont forget the zoiper phone,
the leading IAX and SIP softphone for Windows, Mac, linux and soon windows Mobile.
Posted by anonymous on Thursday, August 02 2007 08:00 AM