Possible abilities provided by a SIP provider:

• SIP address: you get a unique URL like

  sip:yourname@sipproxy.org

  that can be used by other SIP clients to call you, which will cause your SIP client to ring.
• Call-in: a personal POTS number that can be called by normal phones. Also called “phone to pc” calls.
• Call-out: the ability to call POTS phones from your sip phone. Also called “pc to phone” calls.
• Voice mail: if you receive a call and don’t answer it, the message is recorded and emailed to you.

abbeyphone.com¶

Makers of a SIP client plugin for firefox and thunderbird.

ekiga.net¶

Features: SIP address (free), Call-in (paid)

Makers of free software ekiga client.

The call in service for the ekiga client is through www.diamondcard.us

freeworlddialup.com¶

www.freeworlddialup.com

Features: SIP address (not free anymore)

ipkall.com¶

www.ipkall.com

Features: call-in (free)

IPkall provides free Washington State call in numbers that will forward to a SIP address. They don’t provide the SIP address, just the bridge from phone to SIP. IPkall works great with ekiga.

phonegnome.com¶

www.phonegnome.com

The gnome in phonegnome is not related to GNU. Phonegnome lets you place free phone to phone calls (like http://www.jajah.com). It also creates a full SIP profile for you that can be used with any SIP client.

Features: SIP address (free), phone to phone (free), call-out (paid).

sipphone.com¶

www.sipphone.com
www.gizmoproject.com

Features: SIP address (free), Call-in (free), Call-out (paid), Voice mail (free)
Problems: couldn’t get the (callwave based) free call-in to work with any clients other than gizmo, and with gizmo it drops most the incoming calls. They also offer a commercial call-in, maybe that works better?

Makers of commercial gizmo client.

SIPphone is the service that is behind Gizmo. If you use gizmo, everything is already configured. However, if you sign up for a gizmo account, you can then use sipphone’s service on any generic SIP client.

SIP client configuration (from here):

• SIP Proxy: proxy01.sipphone.com:5060 (also called SIP domain)
• STUN server: stun01.sipphone.com:3478
• Username: Your SIP number, found by dialing ** in Gizmo (or checking your profile settings).
• Password: Your password
• Codecs: iLBC, GSM, g711a, and g711u (Gizmo Project uses other codecs as well, but you won’t find them in your hardware settings)
• Outbound Proxy: none

SIP URL:

• sip:____@proxy01.sipphone.com

  , with ____ replaced by your SIP Number or gizmo login.

ekiga
registrar: proxy01.sipphone.com:5060
user: sip number or login
password: gizmo password
authenticated login: sip number or login

wengo
domain: proxy01.sipphone.com
user: sip number or login
password: gizmo password

wengophone.com¶

Features: Call-out (paid)

Makers of free software wengo client.