Three levels of tracing for the SNA links are provided: node tracing, intrinsic tracing, and link-level tracing. Node tracing for SNA Transport is on a node basis and normally is turned off. When turned on, it traces SNA Transport internal events; so, it is a useful tool for troubleshooting SNA Transport. Intrinsic tracing is on a session basis and normally is turned off. When turned on, it traces the send/receive interface between SNA Transport and the SNA services. Because it includes the SNA headers as well as the data, SNA Transport intrinsic tracing is a useful tool for troubleshooting the SNA services. Both types of SNA Transport tracing are turned on and off by using MPE commands. The SDLC link driver also has a trace facility that is useful for troubleshooting SDLC link-level problems; since it drains resources, it normally is turned off. Link-level tracing is turned on and off by using MPE commands. Tracing is described in chapter 5 of this manual; the commands are described in chapter 6.
