Abstract: For the installation configuration and telecommunication network problems and challenges confronted by substation secondary device outdoor installation, the principles of the secondary device outdoor installation configuration are proposed first, which include relay protection within both standalone bay and across bays, bay control unit and public terminal, etc. In addition, two telecommunication solutions are also given based on the above, which include two aspects, the first is the network architecture with MMS/SV/GOOSE network all in one based on parallel redundancy protocol（ PRP）, and the second is high-availability seamless redundancy（ HSR） network which is independent of the switch. Finally, network performance is estimated and compared quantitatively.