Link 7 Technology Research (L7TR) is a research and development company with focus on Internet of Things, Cyber-Physical Systems, Real Time Communications and Data Networks with two flagship products; VPS and PXO.

VPS is a distributed protocol emulator, tester and Quality Assurance (QA) tool that supports several state-of-the-art technologies including: (1) Protocol Emulation: L2, L3, L4 and Application layer protocols, (2) RTC and VoIP signaling via SIP and SIPs, (3) RTC and VoIP media via RTP and SRTP, (4) Emulation and support of media players, media recorders, camera, microphone, text-to-speech (TTS) and automatic speech recognition (ASR), (5) Speech codecs: G.711 MuLaw, G.711 ALaw, G.726, G.723.1, G.729A, GSM6.10, AMR, G.728, G.722, iLBC, Speex, EVRC, GSM-EFR, G.729E, G.729D, LPC, G.722.1/RFC3047, AMR-WB/G.722.2, RTAudio, AAC-LC, SILK, G.718, Opus, iSAC, EVS, (6) Video codecs: H261, H.263 (RFC2190,RFC2429), H.264, H.265, Theora, MPEG-1/2, MPEG-4, Opus, VP8, (7) Tone generation and detection, (8) IoT sensor and actuator emulation, (9) IoT MQTT, CoAP and HTTP support, (10) Impairment insertion at all layers; loss and latency for different distributions including Markov two-state wireless loss model, (11) Software defined protocol emulation (SDPE) with controllers and agents distributed throughout a network, (12) Dynamic, passive and active network quality estimation at all layers including standard VoIP MOS scores, (13) LUA based scripting for customized behavior, (14) Routing, NAT and STUN capabilities, (15) IPv4 and IPv6, (16) Transport Protocols including UDP, TCP, DTLS, TLS and (17) ICMP, DHCP and DNS support.

PXO is the perfect softphone for RTC as it is very flexible with hundreds of configurable features ranging from fax and codecs to voice XML PXO is ideal for SIP and RTP feature testing including latest security enhacements through scripting and automation PXO supports over 25 speech and audio codecs and 8 video codecs.