You basically need a client that will allow SIP to SIP calls outside their network (Skype does not do this):
VOIP "softphone" clients for SIP and IAX2 are available that can easily be dropped into Asterisk/Trixbox for instance.
You can get an AXVOICE PSTN SIP unlimited gateway or trunk [to make calls to people with cell phones and copper phones] (which includes a free Grandstream 286 ATA [hardware device you configure to plug in a phone [more expensive models include a network port for more than one system with the RJ11)]) that can be configured
for Asterisk/Trixbox or a VOIP Client on your desktop, for like $9.00 a
month. http://www.axvoice.com
BEWARE - these don't all do what you might need - read features carefully before choosing one.
Soft Phones (Open Source)
Where the software source code is available for users to use, redistribute and modify.
| Model | Description |
|---|
| ActXPhone | An ActiveX-Control SIP Softphone. |
| BonePhone | Linux SIP softphone in Java. |
| Ekiga | SIP, H.323 audio and video softphone for various unices. |
| GnomeMeeting | H.323 SIP in beta , OpenSource VoIP/Video software for Unix ( win32 coming ... ). |
| IAXComm | IAX2 softphone for Windows, Linux & MacOSX using IAXClient. |
| JsPhone | Java SIP softphone with video support. |
| Kiax | IAX softphone for Linux using QT (runs well also on GNOME), ported to Windows (QT4). |
| KPhone | SIP softphone for KDE. |
| Linphone | Video softphone for Linux and Windows using osip stack. |
| minisip | Softphone for Linux with support for additional security features. |
| Mobile IAX | IAX softphone. |
| MozPhone | IAX addon. Text and URL support, and manager interface. http://moziax.mozdev.org>MozIAX |
| OpenPhone | OpenH323. |
| OpenWengo | . |
| OpenZoep | Softphone engine. |
| Peers | Minimalist SIP softphone written in Java. Tested on Linux and Windows. ITU G.711. |
| PhoneGaim | Linux and Windows softphone with instant messaging, SIP. |
| SFLphone | Multiplatform softphone from Savoir-faire Linux, SIP, IAX. |
| Shtoom | SIP softphone written in Python. Runs on Windows, Mac, Linux. |
| SIP Communicator | SIP Java based softphone. |
| sipXphone | SIP softphone from SIPfoundry, previously known as the Pingtel phone. |
| sipXezPhone | "sipX easy phone", a SIP softphone bassed on sipXtapi. |
| Twinkle | SIP softphone for Linux. |
| wxCommunicator | SIP Windows, C++, based on sipXtapi. |
| YakaPhone | Simple, skinnable IAX/IAX2 and SIP softphone from YakaSoftware. |
| ZiaxPhone | SIP and IAX softphone for the Sharp Zaurus PDA. |
Soft Phones (free, not Open Source)
Soft Phones in this category should be completly free to use and not bound to only one or a few providers.
- 3CX VOIP Phone for Windows Free SIP / VOIP phone for Windows
- Cubix: IAX and SIP)P Protocol support for Windows.
- ((DIAX: IAX protocol softphone, iax1/2 vb client
- Diamondcard.us Softphone IAX Worlds first IAX softphone with a flash interface. Private label available. Easy install.
- ENUM RTC Softphone Windows Softphone with ENUM support
- Express Talk Softphone - Express Talk SIP Softphone for Windows (free)
- http://www.globaliptel.com X-TAPI lite/Pro: TAPI-based SIP Softphone for MS Windows. 9,95 EUR. Also has a free soft phone.
- iaxLite: IAX softphone with AU-100 USB phone set support.
- Idefisk: IAX2
and SIP freeware softphone for the Windows / Linux / MacOS platform
with a focus on small size, small memory footprint and high quality.
- JackenIAX:IAX2 Softphone for Macintosh Mac OS X 10.4.
- MCE SIP Phone A SIP softphone for Windows XP
- MizuPhone A new fully featured and costumizable softphone with G729 codec
- PacPhone Secure Nat-Aware H.323 PBX softphone, Native Nat GnuGK, STUN/UPnP(symmetric) AES256 Encryption,PBX,VoiceMail,USB phones
- Phoner Windows SIP softphone (also supports ISDN cards)
- PhonerLite Windows SIP softphone
- Raketu Voice, DialOut, All messengers, Media Player, SMS, RSS, IPTV/VOD, (Communication, Information, Entertainment)
- sipc: SIP ua for WIndows, Solaris & Linux. Includes support for Video & Whiteboard
- sipLite SIP softphone with G729 codec.
- SIPPS Free: Free lite version of SIPPS
- SJphone: SIP, H.323. Windows, Linux, Mac OS X, Pocket PC.
- Tpad - The Global VoIP Network Free PC Softphone / Dialler for Windows 98/ME/2000/VISTA, SIP softphone with G711 codec.
- Voix Phone Free IAX/AX2 Softphone for Windows, Linux & MacOSX.
- Zoiper IAX / IAX2 and SIP softphone, g729 (optional), customization packages, various features; for Windows, Mac OS and Linux.
- PCBest Network:
An Free SIP ActiveX Control to download. It can be used in IE or Other
Windows application. It support multipul audio codecs and NAT, STUN.
- Zultys phones: SIP softphone for Linux - basic free, extra features chargeable
Why pay for Skype's P2P propritary PSTN minutes?
[Note Beware the "extra charges" on the "free phones" - they usually include PSTN trunk call fees!]
References:
http://www.voip-info.org/wiki-VOIP+Phones