This paper presents a research and development work for the automatic service recording system using network-based monitoring approach. The project is under the cooperation of National Science and Technology Development Agency (NSTDA) and Thai Telecommunication Relay Service (TTRS). The goal is to archive and record video relay services offered to the deaf and hard of hearing community. Using the network-based monitoring approach, we can develop a video recording system that is fully automated and intelligent to analyze different kinds of video relay services. In brief, the system functions to capture network traffic and analyze network packets, signaling, and related protocols such as TCP, UDP, SIP, SDP, RTP, as well as H.264, G.711 encoding. Then, it records the relevant media streams, creates a video file containing the whole video relay service conversation, and send the file to archive in the cloud storage. The benefits include verification in case of appeal, service evaluation, and service improvement. A technical challenge in this system development is how to process real-time interactive multi flows because it must detect and process a large number of call signaling and media streams that occur as interactive real time. The optimization is vital so that the system can swiftly do the processing in time, without causing the buffer overflow problem that can degrade the recording quality. In this regard, we developed a novel methodology for processing PCAP (Packet Capture) called Multiple Buckets Architecture. Our test results showed that it can significantly reduce the probability of buffer overflow, making the processing more efficient when compared to the traditional processing of single bucket.