Cross-Platform SIP Client (Audio/Video, P2P + Conferencing) — iOS, Android, Windows, macOS
Budget: $10,000 – $20,000 USD
I'm looking for an experienced VoIP/SIP developer (or small team) to build a cross-platform SIP client supporting both peer-to-peer calls and video conference joining, with no mandatory registration (registration support required but optional at runtime).
Core requirements:
1:1 P2P SIP calls without registration, plus ability to join video conferences regardless of the conferencing platform
Audio + video with these codecs: Video — H.264, H.265; Audio — Opus, G.711, G.722, G.729 (G.729 if licensing permits)
BFCP for screen sharing
Participant list retrieval (including a proxy approach to read participants from the backend if needed)
Optional SIP registration (built in for future use)
Platforms: iOS, Android, Windows, macOS
Preferred stacks: PJSIP or baresip — propose whichever best meets all requirements
Full source code published to a GitHub repo we own/have access to
Clean, user-friendly UI is a strong plus
Timeline: Hard deadline — end of July 2026.
To apply, please include:
Links to previous SIP/VoIP projects (especially PJSIP/baresip, WebRTC, or telephony apps)
Which stack you'd choose and why
How you'd handle BFCP and the participant-list proxy
Your assessment of whether this timeline is realistic, and your proposed milestone breakdown
Cross-platform experience (how you'd share a core SIP engine across all four platforms)
Core requirements:
1:1 P2P SIP calls without registration, plus ability to join video conferences regardless of the conferencing platform
Audio + video with these codecs: Video — H.264, H.265; Audio — Opus, G.711, G.722, G.729 (G.729 if licensing permits)
BFCP for screen sharing
Participant list retrieval (including a proxy approach to read participants from the backend if needed)
Optional SIP registration (built in for future use)
Platforms: iOS, Android, Windows, macOS
Preferred stacks: PJSIP or baresip — propose whichever best meets all requirements
Full source code published to a GitHub repo we own/have access to
Clean, user-friendly UI is a strong plus
Timeline: Hard deadline — end of July 2026.
To apply, please include:
Links to previous SIP/VoIP projects (especially PJSIP/baresip, WebRTC, or telephony apps)
Which stack you'd choose and why
How you'd handle BFCP and the participant-list proxy
Your assessment of whether this timeline is realistic, and your proposed milestone breakdown
Cross-platform experience (how you'd share a core SIP engine across all four platforms)