Domain-by-domain implementation of Semi-TCP in all-optical networks

Due to the weak buffer capacity nature of all-optical networks, random burst losses may occur, even at low traffic loads. These random burst losses may lead to serious degradation of the TCP performance. Recently, Semi-TCP is proposed to significantly improve TCP performance in multi-hop wireless networks by moving congestion control from transport layer down to the data link layer to realize a hop-by-hop congestion control. Similar to hop-by-hop congestion control in wireless networks, congestion control in all-optical networks can be taken at domain-level. In this paper, we propose a domain-based Semi-TCP for all-optical networks as a possible domain-level solution to TCP performance degradation, in which a TCP connection is split into multiple domains along the path and congestion control is managed domain-by-domain. Besides, the end-to-end reliability control is maintained in the domain-based Semi-TCP. The ingress and egress of each domain implement such a scheme to alleviate the congestion occurring in an optical node and retransmit lost packets if necessary. Through simulation study, we demonstrate that this approach can significantly improve the performance of all-optical networks in terms of throughput.