3Com Baseline 3C16476 User Manual - Page 2

Browse online or download pdf User Manual for Switch 3Com Baseline 3C16476. 3Com Baseline 3C16476 8 pages. Superstack 3 baseline 10/100 switch 48-port 10base-t/100base-tx plus 2-port gigabit

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The numbers in this diagram refer to numbered sections in the text.

Front Panel

48 RJ-45 10/100 Ports and 2 RJ-45 10/100/1000 BASE-T Ports

WARNING: RJ-45 ports. These are shielded RJ-45 data

sockets. They cannot be used as standard traditional tele-

phone sockets, or to connect the unit to a traditional PBX or

public telephone network. Only connect RJ-45 data connec-

tors, 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: Points d'accès RJ-45. Ceux-ci sont pro-

tégés par des prises de données. Ils ne peuvent pas être util-

isés comme prises de téléphone conventionnelles standard, ni

pour la connection de l'unité à un réseau téléphonique cen-

tral privé ou public. Raccorder seulement connecteurs de

données RJ-45, systèmes de réseaux de téléphonie ou télé-

phones 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 données.

VORSICHT: RJ-45-Porte. Diese Porte sind geschützte Dat-

ensteckdosen. Sie dürfen weder wie normale traditionelle

Telefonsteckdosen noch für die Verbindung der Einheit mit

einem traditionellem privatem oder öffentlichem Telefon-

netzwerk gebraucht werden. Nur RJ-45-Datenanscluße, Tele-

fonnetzsysteme or Netztelefone an diese Steckdosen

anschließen. Entweder geschützte oder ungeschützte Buch-

sen dürfen an diese Datensteckdosen angeschlossen werden.

10BASE-T/100BASE-TX Ports

The Switch has 48 auto-negotiating 10BASE-T/100BASE-TX ports con-

figured as Auto MDIX (cross-over). These ports automatically detect

whether they need to operate in MDI or MDIX mode. Each ports

speed and duplex mode (half duplex or full duplex) is automatically

determined by the capabilities of the connected device. The maximum

segment length is 100 m (328 ft) over Category 5 twisted pair cable.

CAUTION: The Baseline Switch supports full duplex

auto-negotiation. If the connected device does not support

auto-negotiation, the Switch will operate in half duplex

mode (even if the device is operating in full duplex mode). 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).

10/100/1000BASE-T Ports

The Switch has two auto-negotiating 10/100/1000BASE-T ports con-

figured as Auto MDIX (cross-over). These ports automatically detect

whether they need to operate in MDI or MDIX mode. These ports

provide 10/100/1000 Mbps full duplex connections to other Gigabit

Ethernet devices. Full duplex allows packets to be transmitted and

received simultaneously which, in effect, doubles the potential

SE THE

ASELINE

Status Yellow = 10Mbps, flashing = activity, Green = 100Mbps, flashing = activity

Port 49, 50 = 10/100/1000BASE-T

WITCH

throughput of a link. These ports require either straight-through or

cross-over Category 5 cables with RJ-45 connectors at both ends. The

maximum UTP cable length is 100 m (328 ft) over Category 5 cable.

The 10/100/1000BASE-T ports will auto-negotiate to the appropriate

speed.

Priority Queuing

The Switch offers priority queuing, meaning all packets that are

received are examined to see if they have been priority encoded. If a

packet has been, then the Switch will read the priority level and

determine whether the packet should be directed through the normal

or high priority channel. 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.

The traffic prioritization feature supported by the Switch is

compatible with the relevant sections of the IEEE 802.1D

standard (incorporating IEEE 802.1p).

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.

Priority Level

Connecting to a Network Device

To connect a device to the Baseline Switch, use Category 5

unshielded or shielded (screened) 100 Ohm TP cable (or Category 3

cable for a 10 Mbps connection). The maximum length of cable for

each connection is 100 m (328 ft). Connect one end of the cable to

an RJ-45 port on the Baseline Switch, and the other end to the

appropriate RJ-45 port on the connecting device.

3C16476 SuperStack 3 Baseline 10/100 Switch Plus Gigabit

Power

Fan

Alert

Traffic Type

Best Effort

Background

Standard (spare)

Excellent Effort (business critical)

Controlled Load (streaming multimedia)

Video (Interactive media), less than 100 milliseconds

latency and jitter.

Voice (Interactive voice), less than 10 milliseconds

latency and jitter.

Network Control Reserved traffic