Hi Steve,
You have absolutely right. The sendnc() is described in spru524i.pdf. Unfortunately it force me to prepare all headers "manually". So, I think about the sendto() once again. Maybe including jumbo support in conjunction with increasing mss variable as you described earlier give the desired behaviour? In this case there should be noerror of mmalloc size. Please tell me what command I have include in ndk.bld to do it. Wiki doesn't explain this option, but I'm sure that the jumbo_pbm.c is not included to the ndk library.
Lech