The OBiTalk portal and the OBiTalk network exhibit similar feature set to the following sip software products: OpenSIPS, SIP Express Router (SER)
OpenSIPS:
http://opensips.org/Main features OpenSIPS can be used as :
SIP registrar server
SIP router / proxy (lcr, dynamic routing, dialplan features)
(OBi dial plans???) SIP redirect server
SIP presence agent
(OBi Dashboard has a status feature) SIP back-to-back User Agent
(OBi network can connect OBi to OBi) SIP IM server (chat and end-2-end IM)
SIP to SMS gateway (bidirectional)
SIP to XMPP gateway for presence and IM (bidirectional)
(OBi, Google Chat???) SIP load-balancer or dispatcher
SIP front end for gateways/asterisk
(OBiTALK Portal) SIP NAT traversal unit
(OBi seems to have this ability as well) SIP application server
SIP Express Router (SER):
http://en.wikipedia.org/wiki/SIP_Express_Routeris a SIP server. It can be configured to act as SIP registrar, proxy or redirect server. SER features presence support, RADIUS/syslog accounting and authorization, XML-RPC-based remote control and others. Web-based user provisioning
(OBi seems to have this ability as well), serweb, is available.
SER's performance allows it to deal with operational burdens, such as broken network components, attacks, power-up reboots
(OBI Expert configuration can reboot the unit) and a rapidly growing user population. SER can be configured for many scenarios including small-office use, enterprise PBX replacements and carrier services.
Some of the other features mentioned in these products might become future enhancements of the OBi.
Just some of my musings about this interesting thread. Anyone see any other similarities?