12.7.2.6 Minimum Throughput Class

Minimum throughput class is set in the Call Request packet as follows:

u_char      min_sendthruput, min_recvthruput;
 /* set min_sendthruput, min_recvthruput to desired values */
 f.type = T_MIN_THRU_CLASS;
 f.f_min_sendthruput = min_sendthruput;
 f.f_min_recvthruput = min_recvthruput;
 error = ioctl(s, X25_SET_FACILITY, &f); 

It is read as follows:

f.type = T_MIN_THRU_CLASS;
 error = ioctl(s, X25_GET_FACILITY, &f);
 min_sendthruput = f.f_min_sendthruput;
 min_recvthruput = f.f_min_recvthruput; 

This facility may only be set in a Call Request packet, and read from an Incoming Call packet. The receiver of the Incoming Call packet should clear the call (with an appropriate diagnostic) if the proposed minimum throughput values cannot be supported.