Director Software Engineer
Current• Completed detailed programming and development tasks for front-end SIP protocol-based controllers, load balancers as well as challenging customized media back-end server code using C, C++ and JAVA with Spring framework.• Designed and coded SIP applications based on business logic.• Retrieved packet frames using FFmpeg demux functions.• Designed and implemented the RTP scheduler and channels.• Programmed RTP Packetizer to send a media payload such as G.711, AMR-NB, AMR-WB, EVS and H.264.• Re-designed and rewrote parsers to support customized MSML and VoiceXML.• Revised the DTMF collector for MSML in a media server.• Added a precondition logic to reserve resources.• Reviewed container formats to save streams into a file and implemented a recording function to support voice mail.• Interfaced with the scenario server using gRPC.• Revised a SIP servlet to support caller tunes and announcement center services working on a web application server such as WebSphere and Tomcat.• Managed hugely, rotated log files using shell script in crontab, and programmed a python script to start a media server process.• Added Prometheus metric information to analyze statistical data.• Completed the aging and performance test using SIPP scripts for 200cps, 15sec call duration, 3000 concurrent sessions target on a server.• Containerized the media server solutions on Docker and Kubernetes environment.• Operated solutions on Linux bare metal, LVS, OpenStack, AWS, Docker and Kubernetes.• Well communicated with QA engineers to manage bugs and set up various test environments.• Cooperated with 10 telecom customers in America, Asia and Europe to solve issues and problems with commercial networks on a supportive 24 hours/7 days basis.
