4.0 OPERATION
This chapter describes the functions and operation of the DFG48000.
4.1 Switching Functionality
A DFG48000 provides switched connectivity at Ethernet wire-speed among all of its ports. The
DFG48000 supports10/100Mbs for copper media and 10 or 100Mb separate traffic domains for fiber
ports to maximize bandwidth utilization and network performance. All ports can communicate to all
other ports in a DFG48000, but local traffic on a port will not consume any of the bandwidth on any
other port. DFG48000 units are plug-and-play devices. There is no software configuring necessary to
be done for basic operation at installation or for maintenance. The only hardware configuration
settings are user options for an UP-LINK Switch (resides inside the unit) on the 6K8-RJ45. Optional
Half / Full duplex mode and 10 or 100Mbps selection for the switched ports must be configured
through MNS software per unit as per the requirement. The internal functions of both are described
below.
Filtering and Forwarding
Each time a packet arrives on one of the switched ports, the decision is taken to either filter or to
forward the packet. Packets whose source and destination addresses are on the same port segment
will be filtered, constraining them to that one port and relieving the rest of the network from having
to process them. A packet whose destination address is on another port segment will be forwarded to
the appropriate port, and will not be sent to the other ports where it is not needed. Traffic needed for
maintaining the operation of the network (such as occasional multi-cast packets) are forwarded to all
ports. The DFG48000 Switches operate in the store-and-forward switching mode, which eliminates
bad packets and enables peak performance to be achieved when there is heavy traffic on the
network.
Address Learning
All DFG48000 units have address table capacities of 4K node addresses suitable for use in larger
networks. They are self-learning, so as nodes are added, removed or moved from one segment to
another, the DFG48000 Switch automatically keeps up with node locations. An address-aging
algorithm causes least-used addresses to fall out in favor of frequently-used addresses. To reset the
address buffer, cycle power down-and-up.
4.2 Status LEDs
For all DFG48000 models:
PWR:
Power LED, ON when external power is applied to the unit.
LK:
Steady ON, Link status for 10 Mbps and 100Mbps operation.
ACT:
ON with port activity for 10 Mbps and 100Mbps operation.
F/H:
Full / Half duplex LED, ON when the port is running full duplex, OFF for half duplex.
100/10:
Speed LED, ON when the speed is 100Mbps, OFF when the speed is 10 Mbps
4.3 Up-link MDI-MDIX on RJ-45 port modules, for port 1 only
The upper part of the copper port module has a manual Up-link switch, located on the inside of the
unit on the port module board next to the RJ45 port # 1 which it controls. It enables the port’s cable
to be cascaded (X) to a 10/100Mb repeater or switching hub in the network. The manual Up-link
switch position is configured as (=) position as default factory setting, where used for all-copper
module or combo modules.
4.4 Auto-Cross (MDIX) and Auto-negotiation, for RJ-45 ports
The RJ-45 ports independently support auto-cross (MDI or MDIX) in auto-negotiation mode and will
work properly with all the other connected devices with RJ-45 port whether it supports Auto-
negotiation or not (e.g. 10Mb Hub, media converter) or fixed mode at 10Mb or 100Mb Half/Full
Duplex(managed switch). No cross-over cable is required while using the DFG480008’s copper port to
other devices. Operation is according to the IEEE 802.3u standard. The Managed DFG48000 Series
Fast Ethernet copper ports, can be set for either fixed 100Mb speed or for 10/100 F/H N-way auto-
negotiation per the IEEE802.3u standard. The selection is made via MNS software. The factory default
setting is for auto-negotiation. At 10Mb or 100 Mb-fixed speeds, the user may select half- or full-
duplex mode by MNS Software for each RJ-45 port separately.