Free SIP Providers 2014
IPTEL, the place where the original SER SIP server was born.The SER was later forked and OpenSIPS and Kamalio (OpensSER) was born. But the SER and OperSER later joined hands again to make the codebase for SER a single entity. We are a bit biased towards IPTEL, because RavenII first dipped his hands in to SIP part of the VoIP IP Telephony with a SER server. In addition to SER, the SIP Express Router, and Free SIP Accounts, IPTEL provides the base SIP Express Media Server and the SIP Express Router Web. The IPTEL site also provides a wealth of information on Sip communication. The free SIP account the IPTEL.ORG provides is of good quality and very easy to register. You can get an account here and follow up to this page to learn how to setup you phone, VoIP client etc to use the free SIP account.
GetOnSIP provides means to conduct audio and video calls in your browser, with absolutely nothing to download. The communications are peer-to-peer (secure). You can Invite people to join you with your instant call link. Since GetOnSIP is compatible with all open-source mobile VoIP (SIP) applications, one can use most SIP applications on your smartphone and make/take calls from anywhere. It also works with downloadable softphone applications on your desktop or notebook. OnSIP suggest Counterpath's Bria and the free Jitsi project for softphone applications..
Your SIP address could also be used on your home or office phone for free voice and video via SIP and they say that the Free SIP address you receive will work with any SIP-based desk phone.Follow this link for an address.
In addition if you are a developer planing to use WebRTC in your app to send and receive voice, video, IM, and/or data, you will be able to use the developer services provided by the Junction Networks. You will be able leverage the geographically scaled OnSIP Network with SIP.JS API, a simple, proven API provided by Junction Networks, to take your app to new heights.
ANTISIP continues to provide very stable free SIP service among other things. antiSIP is a complete SIP service house with multiple services. They also provide clients, SDKs and toolkits which are optimized for NAT traversal (ICE), security (TLS and SRTP) and many other advanced extensions and call control scenarios like supervision, call transfer, call pickup etc. The setting up of the accounts are simple and you on your way to SIP universe, once signed up. Sign up for free account here and explore their other services here.