SERVICE

WebRTC Softphone Development

Browser calling that survives corporate NAT and still lands on your PBX like any other SIP endpoint.

SIP.js / JsSIPICE / TURNWSSClick-to-callEmbedded agentOne-way audio

WebRTC development for a PBX is a signaling + ICE + codec problem. UnifiedPBX.in builds browser softphones and click-to-call that register to FreeSWITCH, Asterisk or FusionPBX, then stay up when the user is on hotel Wi-Fi.

2026 buying brief

Who this is for

SaaS products that promised in-browser calling and now fail on corporate NAT, Safari or one-way audio after hold.

What you get

SIP.js (or equivalent) softphone, ICE/TURN that works off-LAN, click-to-call, inbound toasts and a lab that reproduces the failure.

Searches this page answers

WebRTC softphone development, SIP.js consultant, WebRTC one-way audio, click-to-call in SaaS.

2026 search & AI-search context

In 2026 every vertical SaaS wants a phone in the tab. Most ship a library and no TURN story. The pages that rank name ICE states and the FusionPBX/FreeSWITCH side, not “WebRTC enabled.”

  • A working localhost call is not a product.
  • TURN cost and geo placement belong in the architecture, not the invoice surprise.
  • Hold, transfer and reconnect after laptop sleep are the real acceptance tests.

Reference architecture

Browser to SIP media path
Web app / CRMAuth + click-to-call
Softphone UASIP.js / JsSIP
WSS signalingTLS websocket
STUN / TURNcoturn or managed
PBX WebRTC profileFreeSWITCH / Asterisk
SIP trunks / queues / AISame as desk phones
If TURN is missing, your demo on the same LAN will still look “done.”

Deliverables

Embedded softphone

Mute, hold, transfer, DTMF, device picker, reconnect on network flip.

Click-to-call

Click a number in the CRM; the browser originates through your PBX, not the user's cell.

Diagnostic lab

A SIP.js harness that shows ICE candidates, selected pair and SDP, so “NAT” stops being folklore.

Codec strategy

Opus in the browser, transcode to PCMU/PCMA for stubborn trunks.

Security

Short-lived credentials, WSS-only, no SIP passwords in localStorage if we can avoid it.

Agent UX

Incoming banner, wrap-up codes and presence that match the CCaaS state machine.

FAQ

Questions buyers ask before hiring

Direct answers on scope, stack, rescue vs build, and how to start, structured for search and AI summaries.

Direct answers on scope, stack, rescue vs build, and how to start, structured for search and AI summaries.

Usually ICE/TURN, UDP blocking or asymmetric NAT. We prove the path with browser stats and coturn logs, not only SIP traces.

Yes. Same tenant, same numbering plan, provisioned credentials and TURN, standard in hosted PBX case studies.

Yes. RBAC, hold/transfer, queue login and recording indicators are part of agent panel work.

SIP.js, JsSIP, LiveKit, mediasoup and vendor SDKs depending on tenancy and recording requirements.

Yes. We work from pcaps and SDP: NAT, security groups that open 5060 but not RTP, transcoding, ICE/TURN and REFER/re-INVITE behaviour, not guesswork.

We implement PJSIP/Sofia profiles, digest vs IP auth, OPTIONS keepalives and test matrices your carrier publishes. Legal STIR/SHAKEN attestation is jurisdiction-specific; we implement the technical path your provider supports.

Yes. Send the stack, symptoms and one trace. Upwork and the contact form both work for spikes and rescue work.

Yes. Operators scope hosted IP PBX, CCaaS or CRM+voice they own, source, tenants and recordings stay yours. See contact for VPC, billing and isolation.

Share the current stack (PBX, CRM, cloud), the failure or goal in one paragraph, peak call volume, carriers, and any deadline. Screenshots, a pcap, or a short Loom beat a 40-page RFP. Use the project brief or email hello@unifiedpbx.in.

Yes. Delivery is remote-first from Delhi with scheduled overlap for EU, UK, US and APAC stand-ups. Production changes use written runbooks, rollback steps and agreed maintenance windows.

Need this built?

Send the current architecture, call volume, carriers and the workflow you need to automate or productize. Discovery can start from a broken PBX or a blank product brief.

Discuss Your Project hello@unifiedpbx.in
Related
Case study: React SIP/WebRTC diagnostic lab →Case study: insurance WebRTC →Case study: VoIP CRM / dialer → WebRTC softphone solution →FreeSWITCH WebRTC →Agent panel →WebRTC SIP lab →

Architecture first. Then production.

A practical technical discussion focused on SIP, media, tenants, AI and the delivery path, not a generic sales deck.

Send the brief