1. Check that the orderwire phone is normal.
2. Check that the SC2 is normal.
3. Check whether other NEs have no relevant T2000 interface. The active subrack has relevant interfaces, but the SC2 installed in the standby subrack has no relevant orderwire interface.
4. The orderwire phone can get through only when the SC2 is installed in the active subrack of the OSN 6800. The solution is to install the SC2 in the active subrack.
5. After the SC2 is installed in the active subrack, the orderwire phone still has no ring. After an offhook, the run indicator of the phone is off. Maybe the SC2 fails or the equipment does not support the function.
6. After confirmation, the NE software versions 5.51.01.14 and 5.51.01.15 for the OSN 6800R1 do not support orderwire phones.