TechNote
Number: 03403-03
Date: October 1994
What does an MLID do?
The MLID (Multiple Link Interface Driver) layer hides the complexity of the hardware from the
LSL (Link Support Layer). The MLID layer consists of one or more MLIDs. Each MLID is
responsible for a different type of physical network; for example, token-ring, Ethernet, FDDI,
or Arcnet.
The MLIDs are LAN drivers that have an ODI interface. Madge Networks provide the
following three MLIDs for Madge Smart Ringnodes:
- MADGEODI.COM for DOS
- MADGEODI.SYS for OS/2
- SMART386.LAN for NetWare 386
Each MLID can support a number of physical LAN adapters. In addition, an MLID may
provide a facility known as multiple frame types. Frame types allow you to use various types
of physical header on the same physical LAN adapter. The physical header is the first few
bytes of the frame and usually includes a destination address, source node address, and a
protocol identifier among other things. Novell defines a wide range of frame types to cope
with the various physical headers available with token-ring, Ethernet, FDDI, Arcnet, and
others.
The MLID takes the PID (Protocol ID) from the protocol's request frame and uses this to
create a frame for transmisson. All frame type requests have a 6-byte PID. The PID is a
unique byte sequence that defines the protocol..