The numbers in this diagram refer to numbered sections in the
text. A 24-port unit is shown.
Front Panel
1
24 RJ-45 10/100/1000 Ports
WARNING
: RJ-45 ports.
These are shielded RJ-45 data
sockets. They cannot be used as standard traditional
telephone sockets, or to connect the unit to a traditional
PBX or public telephone network. Only connect RJ-45
data connectors, network telephony systems, or network
telephones to these sockets. Either shielded or
unshielded data cables with shielded or unshielded jacks
can be connected to these data sockets.
AVERTISSEMENT
: Les ports RJ-45.
Ceux-ci sont
protégés par des prises de données. Ils ne peuvent pas
être utilisés comme prises de téléphone conventionnelles
standard, ni pour la connection de l’unité à un réseau
téléphonique central privé ou public. Raccorder
seulement connecteurs de données RJ-45, systèmes de
réseaux de téléphonie ou téléphones de réseaux à ces
prises. Il est possible de raccorder des câbles protégés ou
non protégés avec des jacks protégés ou non protégés à
ces prises de don.
WARNUNG
: RJ-45-Porte
. Diese Porte sind geschützte
Datensteckdosen. Sie dürfen weder wie normale
traditionelle Telefonsteckdosen noch für die Verbindung
der Einheit mit einem traditionellem privatem oder
öffentlichem Telefonnetzwerk gebraucht werden. Nur
RJ-45-Datenanscluße, Telefonnetzsysteme or
Netztelefone an diese Steckdosen anschließen. Entweder
geschützte oder ungeschützte Buchsen dürfen an diese
Datensteckdosen angeschlossen werden.
The Switch has 24/16 10/100/1000 Mbps auto-negotiating ports.
Each port automatically negotiates with the attached device to
determine the correct speed and duplex mode of operation.
Once negotiated, the port will operate in one of the following
modes:
10BASE-T half duplex
10BASE-T full duplex
100BASE-TX half duplex
100BASE-TX full duplex
1000BASE-T full duplex
CAUTION:
The Switch supports full duplex
auto-negotiation. If the connected device does not
support auto-negotiation, the Switch will operate in half
duplex mode, and therefore can only operate at 10
Mbps or 100 Mbps. In such a configuration, you may
notice some degradation of network performance.
3Com recommends that you use devices that are
capable of auto-negotiation (and that you ensure that
auto-negotiation is enabled, if it is a configurable
option).
All ports auto-sense an MDI/MDIX connection so each port can
be connected to a device with a normal ‘straight through’ TP
(twisted pair) cable or a ‘cross-over’ TP cable. Any port can
therefore be used to connect to either another switch port,
server, or workstation without additional configuration.
Traffic Prioritization
The Switch offers priority queuing, which means all packets that
are received are examined to see if they have been priority
encoded. When a packet is received, the Switch will read the
priority level and determine the appropriate channel to forward
the packet based on the priority level. This feature can be useful,
for example, during excessive loads when one type of traffic may
require priority over another. The Switch is configured to comply
with 802.1p, VLAN tagged frames.
Traffic prioritization ensures that high priority data is forwarded
through the Switch without being delayed by lower priority data.
It differentiates traffic into classes and prioritizes those classes
automatically. Traffic prioritization uses the multiple traffic queues
that are present in the hardware of the Switch to ensure that
high priority traffic is forwarded on a different queue from lower
priority traffic, and is given preference over that traffic. This
ensures that time-sensitive traffic gets the highest level of service.
The 802.1D standard specifies eight distinct levels of priority
(0 to 7), each of which relates to a particular type of traffic. The
priority levels and their traffic types are shown in the following
table.
F
EATURES
OF
THE
S
WITCH
5
3
4
2
1
1
13
4
16
5
17
8
9
20
21
3C16479
Switch 2824
12
24
Link/Activity : Green = 1000M, Yellow = 10/100M,
Flash = Activity, Duplex : On = Full, Off = Half
!
2
