of the cross connect 303 and selection of the selectors 105 and 205 by running control programs with user 39 s setting data which are previously stored in a memory 304 the control programs include one of operation control programs shown in fig9 a 10a and 11 a the user 39 s setting data determines the cross connect control information ctrl and the selection information sel 1 and sel 2 as shown in fig7 and 8 an operation of the above described optical transmission equipment of fig5 will be described in detail taking as an example an optical transmission network as shown in fig6 referring to fig6 it is assumed that the optical transmission network is composed of optical transmission equipments ote 1 ote 5 which are connected in series such that the optical transmission equipments ote 1 and ote 2 are connected by an optical line l 1 the optical transmission equipments ote 2 and ote 3 by an optical line l 2 the optical transmission equipments ote 3 and ote 4 by an optical line l 3 and the optical transmission equipments ote 4 and ote 5 by an optical line l 4 the optical transmission equipments ote 2 ote 4 work in a communication protocol a e g tcp ip and the optical transmission equipments ote 1 and ote 5 work in a different communication protocol b e g osi accordingly the optical transmission equipment ote 2 is connected to the optical transmission equipment ote 1 working in the different communication protocol b and to the optical transmission equipment ote 3 working in the same communication protocol.