Cisco Cisco Ciena Corporation Ericsson Nokia Siemens Networks Current work on wavelength switched optical network includes several considerations regarding the interface signal compatibility. In particular ingress and egress optical interfaces will require a check on several optical parameters to assess if the signal generated by the ingress interface can be compatible with the receiving interface. Current solution available encode all parameters in WSON protocol extensions while in this draft will propose an alternative method to keep into account the signal compatibility issue at protocol level.