Halcyon vs SessionTalk Softphone

Halcyon is a free, pre-1.0 Android softphone built on PJSIP and integrated with Android Telecom. It registers with a PBX over UDP, TCP, or TLS, advertises RFC 8599 push parameters, and supports several SIP identities with an account selected for each call. When server-side push is configured, the registrar sends a data-only FCM message before an incoming INVITE to wake the device. Without push, Halcyon uses a foreground SIP service with permanent TLS registration and the associated battery cost. Its Android ConnectionService handles tel: and sip: calls, including from the lock screen, while Telecom-native routing supports Bluetooth headsets and Android Auto. Listed audio codecs are Opus, G.722, AMR-WB, and G.729; video codecs include VP8, VP9, and arm64 MediaCodec H.264. Media uses SRTP encryption, with ZRTP on the roadmap. Android 8.0 or newer is required; signed APKs are available from GitHub Releases.

SessionTalk Softphone provides native softphone apps alongside SessionPBX, which combines voice and video calling, team messaging, and hosted PBX service. Apps are listed for Android, iOS, macOS, web, and Windows. The softphones can connect to SIP-based PBX and hosted platforms, including Asterisk, FreePBX, FusionPBX, 3CX, FreeSWITCH, Kamailio, OpenSIPS, BroadSoft, Metaswitch, PortaOne, VitalPBX, and Yeastar. Calling supports up to six concurrent calls, transfer, recording, and HD video using H.264, VP8, or VP9. Depending on plan and setup, messaging may include direct and group messages, file sharing, and SMS through a SIP provider. Teams Phone and Teams Business include hosted phone service, but customers provide their own SIP carrier for external calls and pay that carrier directly. Setup can use a mobile QR code or a one-time desktop link. A 14-day trial includes full feature access and requires no credit card. Monthly plans include Teams Phone at $20 a month, Teams Business at $40 a month, Generic at $100 a month, and white-label mobile or desktop at $400 a month each.