PortSIP Softphone is a SIP-based softphone for iPhone that uses Wi-Fi or 4G/LTE connection to make and receive calls and Instant Messages.

Interworking with PortSIP PBX, PortSIP Softphone support push notification, which allows it receive calls and messages even it was force terminated.

By using iPhone's existing contact list, PortSIP Softphone facilitates easy and effective communication management with an intuitive interface which accommodates multiple calls. Call functionality includes the ability to switch between two calls, merge and split calls and perform attended and unattended transfers. It also supports video conference which needs MCU support.

PortSIP Softphone incorporates advanced security settings which allows for secure call signaling and audio encryption.

It supports up to 1080P video call with H.264 and VP8 codec, and supports HD audio call. Codecs offered includes: G.279, G.711a/u, Opus, AMR, AMR-WB, G.722.1, iLBC, GSM, SPEEX-WEB.