Abstract: To solve the interoperability problems caused by numerous IoT devices and protocols with varying architectures and application scenarios,this paper proposes an efficient and scalable application layer protocol conversion approach.This approach uses protocol packet parsing and key method mapping for widely used HTTP and other three protocols.Considering the significant differences in the underlying architecture,message format,communication mode,and application scenario of the four protocols,the proposed approach solves the uniformity of information storage for different protocols by parsing the original data pa-ckets of the protocols and extracting key information,and storing the information in the form of key-value pairs.By constructing the key method mapping table,the methods of different protocols are mapped,realizing the interconnection between different protocols.Experimental results show that the proposed approach performs well in message conversion between the four protocols.It demonstrates a significantly improved conversion speed compared to the Ponte method of a comparable type,with a nearly 10-fold difference observed in some cases when subjected to the same test conditions.Furthermore,it supports twice as many conversion types as Ponte.Experimental results show that the proposed method outperforms state-of-the-art methods in terms of scalability and efficiency.

Key words: Internet of things, Application layer protocol, Protocol conversion, Interoperability