The most relevant SIP softphones are:
- Linphone (GPL, * nix / windows)
- SFLphone (GPL, * nix)
- X-Lite (proprietary, windows / mac)
- MicroSIP (GPL, windows)
- Telephone (BSD license, mac)
- Jitsi (LGPL, java, cross-platform)
- CSipSimple (GPL, android)
- Codec Pack for CSipSimple – Additional codecs for CSipSimple, including the newest and most advanced codec “Opus”
- siphon (GPL, iOS)
- 3CXPhone (???, windows / android / iOS)
Several examples of hardware SIP solutions:
- http://voips.ru/linksys-by-Cisco-spa3102.html – a SIP trunking gateway that allows you to connect 2 regular phones to 2 independent SIP accounts and use them without communication with a PC. Supports CallerID. Allows the use of SipBroker regardless of the dial plan (dial plan support).
- http://www.gigaset.com/en_US/shop/gigaset-a510-ip.html – home DECT phone with SIP protocol support.
- http://www.youtube.com/watch?v=ngo84_YJrNE – a small demonstration of the SIP-videophone Grandstream GXV-3175.
The full list of manufactured SIP-compatible equipment can be found on the web.
(Probably the most useful categories are “SIP phones” and “VoIP gateways”). When choosing, preference should be given to well-known and proven brands (Linksys, D-link, Cisco, Gigaset, GrandStream, etc.
For the Advanced users, wishing to set up their own server, we can recommend FreeSWITCH – a very powerful system with rich features. Open source, cross-platform, support for configurable voice menu “out of the box”, good documentation on the site.
Several well-known SIP providers:
The Most Common Problems Connected With Popular SIP Softphones
If your client registration on the server proceeded ok, but the calls do not pass through one or both sides or one-sided audibility is observed, the source of the problems is most likely a badly configured firewall or a hard-locked NAT that does not support transparent operation with such services.
First, make sure that your microphone is all right, as described earlier. Try disabling the firewall. Check if STUN is specified.
Separately, we can distinguish the situation, when incoming calls are working right after connection, but stop to pass after a few minutes of downtime. In this case, the solution is to keep the time “keepalive” in the client.
After each step, do not forget to reconnect to the server (if it’s a softphone – just restart it).