Integrated Local Management Interface Daemon (ILMID)

The ILMID, or Integrated Local Management Interface Daemon, provides an interface to each ATM device for status information, parameter configuration, and address registration. It uses the SNMP protocol for communication with its peer. The ILMI protocol implemented in ILMID provides a 2-way exchange of parameters, configuration information, and address registration across an ATM User Network Interface ( UNI) between a host and a switch. As such, it is a subset of the full protocol specified by the ATM Forum specification af-ilmi-0065.000 entitled Integrated Local Management Interface (ILMI) Specification Version 4.0. For example, it only provides the host side Interface Management Entity (IME) functionality. It is currently used only to achieve the automatic address registration needed by SEAN. ILMID is implemented as a daemon, and is composed of three parts. The first part called TopTerm serves as a booting module whose main function is to generate the events StartVisitor and LinkUpVisitor and to send them to the ilmi module. The second part, ilmi module, implements the ILMI protocol finite state machine and acts as a manager for the retrieval of object identifiers outside of the ILMI Management Information Base MIB. This is done by delegating any SNMP request for non-local object identifiers to an SNMP object built using the HP SNMP++ library. The third part , LowTerm binds the $(0,16)$ ILMI connection to a file descriptor and translates outgoing events to WRITEs and incoming READs into events and send them to the ilmi module. READ/WRITE are carried using the XTI interface implementation on top a FORE systems driver.

Figure 2.6: ilmi daemon FSM