Abstract-Internet data is transmitted in variable-size packets to provide flexibility for different applications. There has been a growing interest in developing the design of Internet routers based variable-lenght packets to improve performance and reduce the amount of re-assembly memory. However, most of variable-length designs follow a time-slotted approach, which make them similar to routers that switch fixed-length packets. The use of slotted timing makes padding necessary when packet sizes are not proportional to the time-slot length. In this paper, we investigate the impact of concatenating packets to reduce the amount of padding in variable-length packet switches. This approach increases the utilization of interconnection bandwidth and overall throughput performance. Performance evaluation in an input-queued packet switch using packet concatenation is presented.Index Terms-Packet scheduling, input-queued switch, variable length packet, cell switching, packet-based scheduling, packet concatenation.

The transmission of digital video requires a large amount of bandwith. Such bandwiths are typically not available on typical computer networks. Apart from bandwidth, variable network latency has a considerable effect on video transmission. However the human vision system is fairly tolerant to relatively poor quality moving images. It is argued that there are practical applications that can benefit from the ability to transmit low quality video images over general purpose computer networks. The generally improving network bandwidths and increasingly powerjiul digital video compression techniques make the whole problem practical. A protocol is proposed that can adapt to the available bandwidth and can tolerate some loss of data during transmission.