High Quality Content by WIKIPEDIA articles! Shared Risk Resource Group (commonly referred to as only Shared Risk Group or SRG) is a concept used in Optical mesh network routing. However it is not limited to Optical mesh networks; SRG’s are also use in MPLS, IP networks, and Synchronous Optical Networks as well. SRG is the concept that different networks may suffer from a common failure if they are sharing a common risk or a common SRG. An SRG failure causes multiple circuits to go down because of the failure of the common resource being shared by those networks. There are three main types of Shared Risk Groups: Shared Risk Link Group (SRLG), and Shared Risk Node Group (SRNG), and Shared Risk Equipment Group (SREG).