1998YD/T 974-1998 Specifications and Measurement Methods for SDH Digital Cross Connect Equipment (SDXC)
1996YDN 002-1996 Technical requirements for SDH digital cross-connect equipment (SDXC) (provisional regulations)
YDN 002-1996 Technical requirements for SDH digital cross-connect equipment (SDXC) (provisional regulations) was changed to YD/T 974-1998 Specifications and Measurement Methods for SDH Digital Cross Connect Equipment (SDXC).