FAQ
Common questions about Siperb — how it works, what’s free, and how to get connected. If you can’t find what you’re looking for, visit the Support page.
General
What is Siperb?
Siperb is a WebRTC softphone platform — a browser-based, desktop, and mobile phone application that connects to your existing PBX or VoIP provider. It comes in three forms: a Web Phone SDK for developers, a ready-made softphone for end users and IT admins, and a co-branded version for businesses who want to offer it under their own brand.
What platforms does Siperb run on?
Siperb runs on Web (any modern browser at /phone/), Desktop (Windows, macOS, and Linux via Electron), and Mobile (iOS and Android via React Native). All three share the same core features and connect to the same backend.
Is Siperb open source?
The core Browser Phone SDK and the web-deployed code are open source. The mobile apps and the Siperb cloud service are not.
Connecting to your PBX
Do I need my own PBX?
Siperb works best when connected to a PBX — either your own on-site server or a hosted one. It does not have to be Asterisk; any SIP-capable PBX will work. If you do not have a PBX, you can also connect to a hosted VoIP or SIP trunking provider.
Does my PBX need to be WebRTC-enabled?
It depends on which registration mode you use. In WebSocket (Direct) mode, Siperb connects directly to your PBX, so your PBX must support WebRTC — specifically TLS signalling and SRTP media. In Proxy (Transcoding) mode, Siperb’s proxy sits between your softphone and your PBX, handling the conversion between WebRTC and standard SIP. In this case, your PBX only needs to support regular SIP — no WebRTC required.
What is the difference between Proxy Registration and WebSocket Registration?
These are Siperb’s two registration modes. In WebSocket Registration, your softphone connects directly to your PBX over a WebSocket — no Siperb infrastructure involved after the initial setup. In Proxy Registration, your calls are routed through Siperb’s SBC (Session Border Controller), which handles transcoding, NAT traversal, and push notifications on your behalf. Both modes are available on all plans, including the free Personal plan.
Can I connect to a hosted VoIP provider like Twilio or my own ITSP?
Yes. You can connect Siperb to any SIP-capable provider, including Twilio, Vonage, or your own ITSP. Use an Outbound Trunk connection with Proxy Registration mode — Siperb’s proxy handles the media transcoding between WebRTC and the provider’s standard SIP infrastructure.
Plans and pricing
Is Siperb free to use?
Yes. The Personal plan is free and includes everything you need to make and receive calls — both registration modes, proxy, media transcoding, and push notifications. There are no time limits and no feature restrictions on the core softphone functionality.
What do paid plans add?
Paid plans extend the platform in two areas: data retention and user management. The Business plan adds Domain Users (managed staff accounts under your domain) and extends cloud data retention to six months, including longer SIP Trace logs. Business Pro extends retention to five years and adds AI-powered transcription and call assistant tools. See the Pricing page for current costs.
Can I self-host Siperb?
No — Siperb is a cloud-hosted service. That said, the Personal plan is free, so there is no cost to using the hosted version for core softphone functionality. If you want to embed a self-hosted phone in your own application, the open-source Web Phone SDK (see web-phone) may be what you’re looking for.
Domains and users
What is a Domain User?
A Domain User is a managed account that sits under your Siperb domain. As a domain owner, you can create Domain User accounts for your staff or customers, configure their connections, and control their access. Domain Users are a Business plan feature — each seat is paid for by the domain owner above them, not by the user themselves.
What is Identity Verification and when is it required?
Identity Verification uses Stripe Identity to confirm who you are before certain actions are enabled. It is required when adding Domain Users to your account and when using user-to-user dialling features on the Siperb network. Verification is a one-time process: you scan a QR code on your phone and photograph a valid ID document.
Getting help
Where can I get support?
Start with the Knowledge Base — most common setup questions are covered in the articles for your section (Web Phone, Siperb Softphone, or Co-branded). For direct support, visit the Support page. Business and Business Pro users have access to priority support tickets.
Is there a community or forum?
Yes. The Siperb community forum is accessible from the Support page. It’s a good place to ask questions, share configurations, and see how others are using Siperb in their setups.