Softphone

Short answer: A softphone is software that makes and receives phone calls over the internet, usually using SIP, on a computer, tablet or smartphone. It replaces a desk phone with an app: you enter SIP credentials, it registers to the provider, and you can dial and answer calls through a headset or speakers.

Softphones range from free open-source apps to paid business clients. All of them need the same small set of details from your provider.

Definition

The name contrasts software with hardware phones. A softphone implements the SIP user agent, audio codecs and a dial pad in an application.

How it works

  1. Enter the SIP server, username and password.
  2. The app registers so incoming calls can find it.
  3. Outgoing calls are sent as SIP INVITEs; audio is encoded with a shared codec such as G.711.

How it applies to ZuteSIP

Any SIP-compliant softphone works with a ZuteSIP number. Guides on the site cover Zoiper, Linphone, MicroSIP, Bria and Groundwire. ZuteSIP does not publish its own mobile app; if you would rather install nothing, the browser web dialer lets you call from any of your numbers.

Softphone vs web dialer

SoftphoneWeb dialer
InstallAn app such as Zoiper, Linphone, MicroSIP, Bria or GroundwireNothing; it runs in the browser
SetupEnter the SIP server, username and passwordSign in to the dashboard

Related terms

  • SIP
  • Web dialer
  • Codec G.711
  • NAT and STUN

Frequently asked questions

Is a softphone free?

Many are, such as Linphone and MicroSIP; others, like Bria, are paid. The number and SIP service are billed separately by your provider.

Do I need a softphone to use ZuteSIP?

No. You can use the browser web dialer, forward calls to any phone, or read SMS in the dashboard.

Why can I call out but not hear audio?

One-way or missing audio is usually a NAT problem. Enabling STUN or switching to TCP or TLS often fixes it.

Can I use the same number in two softphones?

Behaviour with multiple registrations depends on the setup; the SIP troubleshooting guide covers common cases.

Related pages