Mobile SIP SDK – Application Development

With the ever-changing, fast moving environment of Mobile Communications, many Over-The-Top (OTT) applications such as Skype, Viber, Facebook, and WhatsApp have emerged and become popular players in the same market. This new scenario features big challenges for carriers and operators to keep their relevance but also represent a great opportunity for developers of mobile applications to offer a variety of solutions for fixed and mobile Service Providers – such as HD voice, video calling, conference, location sharing, instant messaging, and file transfer.M5T provides Voice and Video over LTE (VoLTE) and Rich Communication Suite (RCS) through its comprehensive and cost-effective Software Development Kits – Mobile SIP SDKs. We provide complete, interoperable, secure and high-value SDKs that allow our customers to focus on their unique applications and achieve time to market, without the need for complicated integrations or deep VoIP know-how.

M5T SIP Client Engine SDK

A complete C++ SIP Client implementation that handles SIP signaling details and abstracts Media Management, SDP negotiation and XCAP handling, allowing developers to focus on the user/device interface and management functionality. Media side can be implemented by customers to integrate the SIP Client Engine on any type of SoC (DSPG, TI, etc.).Our solution is compliant with the stringent international standards and our protocol stacks ensure support and high quality for multiple communication formats of Voice, Video, Instant Messaging, Presence, and Media Sharing.

Key Features


Make and Receive Calls, Caller ID, Anonymous Call Rejection, Call Forwarding, Call Blocking, Call Waiting, Call Hold, Call Transfer, Three-Way Calling, Distinctive Alerting, Message Waiting Indicators, and Emergency Call Handling.


Video Calls, HD Voice Calls, Video Conference, Video Streaming, Chat/Group Chat, Presence, Image and Files Sharing, Fax and Modem over IP, and Secure Communications.

IETF, IMS, RCS, VolTE, And PacketCable

Our SDKs are deployed in a wide range of networking scenarios, whether it is for custom-based, IETF-based, or IMS-based telecommunication networks. They also allow several options of run-time and compile-time configuration parameters.



M5T SIP Client Engine SDK is an ideal solution for building an over the top (OTT) SoftClient running on an iOS, Android, or WindowsPhone-based smartphone or tablet. Let M5T SIP Client Engine take care of the standards, so you can focus on what makes your application unique.

Flexible APIs

From a simple SIP Softphone to a more advanced IMS, VoLTE or RCS/Joyn solution, M5T SIP Client Engine will provide you with a strong base portable on current major mobile operating systems allowing you to deploy on the broadest possible set of devices.


M5T SIP Client Engine comes with its own fully integrated media engine, based on the media engine from the WebRTC project. Do you want to use a different media engine? M5T SIP Client Engine is modular and can adapt your interface to our APIs.

Secure Signaling And Media

Security being an important aspect for communications, M5T SIP Client Engine SDK supports TLS 1.2, SDES-SRTP or MIKEY key negotiation, and SRTP, easing deployment in corporate networks.