PulseSIP turns your iPhone into a full-featured SIP desk phone — no dedicated hardware required. Connect to any standard SIP server, Asterisk PBX, or hosted VoIP provider and start making calls in minutes. FEATURES: Reliable Calling • Register with any SIP server using standard credentials • Make outgoing calls by typing a number or full SIP URI • Full-screen incoming call screen with Answer and Decline • Auto-registers on launch so you're always reachable Professional In-Call Controls • Mute microphone with a single tap • Hold and resume calls using SIP re-INVITE • In-call DTMF keypad for navigating IVR menus and phone trees • Real-time call duration timer Maximum DTMF Compatibility PulseSIP sends DTMF tones three ways simultaneously — RFC 2833 (out-of-band RTP), SIP INFO, and inband audio — ensuring reliable digit delivery regardless of your server's DTMF mode setting. Call History • Recents list with incoming, outgoing, missed, and declined calls • Tap any entry to call back instantly • Swipe to delete individual entries or clear all history NAT & Network Traversal • Built-in STUN support • ICE (Interactive Connectivity Establishment) for complex NAT scenarios • DNS SRV lookup for enterprise SIP deployments Native & Lightweight • Built entirely in SwiftUI with a clean, familiar iOS interface • No CallKit — works without special entitlements or carrier agreements • Credentials secured in the iOS Keychain • No subscriptions, no accounts, no tracking WHO IS IT FOR? PulseSIP is designed for developers, IT administrators, and power users who need a straightforward SIP client to test and use VoIP infrastructure — whether that's an Asterisk server, FreePBX, Kamailio, or any other standards-compliant SIP registrar. REQUIREMENTS • An active SIP account with a registrar server • iOS 18 or later • Wi-Fi or cellular data connection