Lltd, Lpd/lpr, Lltd -9 lpd/lpr -9 slp -9 – Konica Minolta bizhub C25 User Manual

Page 256: Network printing 8-9

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Network Printing

8-9

LLTD

The acronym for Link Layer Topology Discovery, which is a technology
investigating how the devices on the network are connected. Network
devices with this technology are recognized by Windows 7/Vista/Server
2008 on the network, and displayed as icons configured on the network map
of Windows 7/Vista.

LPD/LPR

LPD/LPR (Line Printer Daemon/Line Printer Request) is a platform-
independent printing protocol that runs over TCP/IP. Originally implemented
for BSD UNIX, its use has spread into the desktop world and is now an
industry standard.

SLP

Traditionally, in order to locate services on the network, users had to supply
the host name or network address of the machine providing the desired ser-
vice. This has created many administrative problems.

However, SLP (Service Location Protocol) simplifies the discovery and use
of network resources such as printers by automating a number of network
services. It provides a framework that allows networking applications to dis-
cover the existence, location, and configuration of networked services.

With SLP users no longer need to know the names of network hosts.
Instead, they need to know only the description of the service they are
interested in. Based on this description, SLP is able to return the URL of the
desired service.

Unicast, Multicast, and Broadcast

SLP is a unicast and a multicast protocol. This means that messages can be
sent to one agent at a time (unicast) or to all agents (that are listening) at the
same time (multicast). However, a multicast is not a broadcast. In theory,
broadcast messages are “heard” by every node on the network. Multicast
differs from broadcast because multicast messages are only “heard” by the
nodes on the network that have “joined the multicast group.”

For obvious reasons network routers filter almost all broadcast traffic. This
means that broadcasts that are generated on one subnet will not be “routed”
or forwarded to any of the other subnets connected to the router (from the
router’s perspective, a subnet is all machines connected to one of its ports).
Multicasts, on the other hand, are forwarded by routers. Multicast traffic
from a given group is forwarded by routers to all subnets that have at least
one machine that is interested in receiving the multicast for that group.

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