Research And Design Of DNS-based Service Discovery Technology

Computer science is under the new mode of pervasive computing,devices of different abilities will be gradually integrated into people's daily life in a natural method.In this background,research on service discovery technologies become increasingly important.Existing service discovery solutions have common issues of interoperability and scalability.As the most widely used service discovery framework,DNS is naturally considered a good way to solve the problem.Today's DNS-based service discovery has been widely used in local area,but can still not be well extended to the Internet because lack of standards for service registration and advertisement.In order to use the technology to achieve wide area service discovery,this paper design a solution based on some existing mechanisms:add mDNS service directory to store service information in local area,and also a mDNS proxy for conversion between multicast and unicast.In the Internet,use DHCP and domain enumeration to advertise service,modify DNS server configuration for dynamic updates and then configure client to discovery service based on DNS dynamic updates mechanism.In particular,with the rapid development of IoT,billions of constrained devices will connect to the Internet,which presents new challenge to DNS service discovery.This paper further do a extend research on DNS service discovery in constrained environment,and propose to take DNS server as sleep proxy to solve the sleep node problem.Also,the paper describe how to compress domain name,SRV query and TXT query in DNS packet to optimize the transmission efficiency.At last,the paper give a verification of the wide area DNS service discovery solution.And then analyze the sleep node solution in the Contiki simulation environment.Finally,the paper compare the effects of different optimization schemes by using Avahi.