3Com 3C16476-US User Guide - Page 2

HOW TO USE THE BASELINE SWITCH Status Yellow = 10Mbps, flashing = activity, Green = 100Mbps, flashing = activity Port 49, 50 = 10/100/1000BASE-T 1 25 2 26 3 27 4 28 5 29 6 30 7 31 8 32 9 33 10 34 11 35 12 36 13 37 14 38 15 39 16 40 17 41 18 42 19 43 3C16476 SuperStack 3 Baseline 10/100 Switch Plus Gigabit 20 44 2145 22 46 2347 24 48 Power Fan Alert 49 50 The numbers in this diagram refer to numbered sections in the text. Front Panel 1 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 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: Points d'accès 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 données. VORSICHT: 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. 10BASE-T/100BASE-TX Ports The Switch has 48 auto-negotiating 10BASE-T/100BASE-TX ports configured 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 configured 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 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 0 1 2 3 4 5 6 7 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 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. 2