FriendCaller is SIP (Session Initiation Protocol) compatible (RFC 3261). It is used by most popular VoIP providers, and supported by nearly all key VoIP players including Cisco, Vonage, Comcast, Motorola, Nokia and Huawei.

You can use the same FriendCaller credentials that you use for FriendCaller apps for iPhone, Android, as well as the FriendCaller WebPhone at FriendCaller.com, with most currently available SIP devices. You can also search for a free SIP client, SIP for Android devices, and other SIPs for mobile phones.

Please tell us about your experience when using FriendCaller with SIP devices, SIP clients, SIP phones, IP phones, or softphones, by e-mailing us. We have received reports from users for a wide range of SIP-based hardware and software programs including Aastra, Asterisk, Avaya, AVM, Broadtel, BroadVoice, Cisco, Fritzbox, Grandstream, Lingo, Linksys, Motorola, Nokia, Planet, Polycom, Polypower, ShoreTel, Siemens, SNOM, T-COM, Vtech, Vonage and Zoom. At this time, we are unable to provide support for all these VoIP devices. However, your feedback will be collected an evaluated for future updates to our services.