Communication with input/output system devices

A computer program product is provided for performing: obtaining, by a channel subsystem, a transport command word (TCW) specified by an operating system, the TCW comprising an address of a transport services request block (TSRQB) and an address of a transport services response block (TSRSB); obtaining the TSRQB; building at least one command request based on the TSRQB, and sending the at least one command request from the channel subsystem to at least one network entity, the at least one command request including at least one of a fiber-channel generic services (FC-GS) request, a fiber-channel link services (FC-LS) request, and a fiber-channel link-level function (FC-SB) request; receiving a response to the at least one command request from the at least one network entity; and storing the response to the TSRSB based on the address of the TSRSB obtained from the TCW.