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Data Link Provider Interface (DLPI)
Data Link Provider Interface (DLPI)
Copyright © 1997 The Open Group
Guidelines for Protocol-independent DLS Users
DLPI enables a DLS user to be implemented in aprotocol-independent
manner such that the DLS user can operate over many DLS providers without changing
the DLS user software. DLS user implementors must adhere to the following
guidelines, however, to achieve this independence:
-
The protocol-specific service limits returned in the DL_INFO_ACK
primitive (for example,
dl_max_sdu)
must not be exceeded. The DLS user should access these
limits and adhere to them while interacting with the DLS provider.
-
Protocol-specific DLSAP address and PPA identifier formats should be
hidden from DLS user software. Hard-coded addresses and identifiers must be
avoided. The DLS user should retrieve the necessary information from some other
entity (such as a management entity or a higher layer protocol entity) and insert
it without inspection into the appropriate primitives.
-
The DLS user should not be written to a specific style of DLS
provider (that is, style 1 versus style 2). The DL_INFO_ACK returns sufficient information to
identify which style of provider has been accessed, and the DLS user should
perform (or not perform) a DL_ATTACH_REQ accordingly.
-
The names of devices should not be hard-coded into user-level
programs that access a DLS provider.
-
The DLS user should access the
dl_service_mode
field of the DL_INFO_ACK primitive to determine whether connection or connectionless services are
available on a given stream.
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