Hubs and Switches

• What does the "VLAN" function mean on your smart switches?
  The VLAN function means that this layer 2 management switch could be configured, based on MAC addresses of workstations or port numbers on this switch, to have some different VIRTUAL NETWORK GROUPS in one physically same network. Broadcasted and unicasted data packets will be sent to their owned virtual network groups only to provide more network security and reduce the network traffics among any other virtual network groups.This is a very important feature which could be used to reduce broadcasted traffics on network and integrated with network security accordingly onto the setting of virtual network groups.
• What does the "Trunking" function mean on your smart switches?
  The Trunking means that the layer 2 management switch could be configured to have some ports on that switch to be one same data trunk to other same trunking switch devices, and to send any one data splitedly onto those ports at the same time simultaneously to other same trunking switch devices. This is a very important feature which could be used to increase the data bandwidth as times with number of ports in trunk between any two trunking switch devices. Trunking function means to have some multiple ports to be one same trunk for data transferring from one network switch to another network switch with the same trunking feature and trunking settings. Then, these two switches could have aggregated bandwidth as one channel (two way of port to port) multiply by number of connection between those ports set in this one trunk between them. It provides times the network speeds (connections x 200 Mbps) than only one connection between any two normal switches (only 200 Mbps) to solve the lacking of bandwidth problem.
• Could your smart switches be managed with any third party network management software?
  Our current VLAN switches work as port based or MAC based layer 2 VLAN and Trunking switches and this is depended upon how you configure it to work through the console port on our VLAN switches. They are not Layer 3 switches which support SNMP, tagging or TCP/IP protocols. Therefore, our current VLAN switches could not be managed by any other management software from any third party companies based on TCP/IP, SNMP protocols or taggings protocols.

  Simple rules for Fast Ethernet Hub trouble shooting

  •  Check if hub follow connectivity rules, Class II hub only allows two hubs connected together.
  •  Check the maximum cable length and connector securely fasten or not.
  •  Cabling should be certified as Category 5 UTP or STP.
  •  Check correct methods to linking device, using straight cable or crossover cable., through normal port or uplink port.
  •  Check LINK LED status on the panel
  •  Because Hub is shared device, so it only has half-duplex mode.
  •  Check driver if installed successfully, in Windows 95/98 you should check "Control Panel" -> "Networks".
• When do I choose Crossover or Straight-Through cable ?

  Hub/Switch	Connected device	Port type	Cable
  Normal port	Hub/Switch	Normal	Crossover
  Normal port	Hub/Switch	Uplink	Straight
  Normal port	NIC	-	Straight
  Uplink port	Hub/Switch	Normal	Straight
  Uplink port	Hub/Switch	Uplink	Crossover
  Uplink port	NIC	-	Crossover

• What is Fast Ethernet?
  Fast Ethernet technology use CSMA/CD network access protocol, is IEEE 802.3u standard for 100Mbps Ethernet network, fully compatible with original Ethernet standard IEEE 802.3. There are three media specification standard: 100Base-TX, 100Base-T4 and 100Base-FX. The 100Base-TX supports 2-pairs of category 5 UTP cable and 100Base-T4 supports 4-pairs of category 3/4/5 UTP cables and 100Base-FX supports fiber optic cabling in Fast Ethernet networks.
• What is Dual-Speed Hub?
  The Dual-Speed Ethernet Hub complies with both IEEE 802.3 10Base-T 10Mbps Ethernet and IEEE 802.3u 100Base-TX 100Mbps Fast Ethernet standard and support auto-sensing capability to automatically detect 10Mbps or 100Mbps speed. Dual-Speed Hub allows all of ports connected with either 10Mbps or 100Mbps to communicate each other, but prohibit some ports with 10Mbps and some ports with 100Mbps.
• What is Dual-Speed Hub with switch port?
  This kind of Dual-Speed Hub has one switch port built-in inside. It allows 10Mbps Ethernet and 100Mbps Fast Ethernet connected with this hub and able to communicate each other simultaneously.
• What is Switch Hub?
  A switching hub can be considered to represent a multiple-port bridge, with a complicated internal bus that allows full cross-point switching. Such a hub has low latency packet delay and allow several conversations simultaneously. It has larger bandwidth than hubs.
• What is Stackable Hub?
  A stackable hub is a product which could provide expandable number of ports to achieve your requirements. Each hub within same stack is considered one repeater count, so it could be a good solution for repeater count limitation.
• What is auto-negotiation (N-Way)?

  The IEEE’s auto-negotiation technology, also known as N-way, can tell what speed the other end of the wire is capable of. The hub or NIC will then automatically adjust its speed to the highest common denominator, that is, the fastest speed that both are capable of. Auto-negotiation defines five modes: 10Base-T half duplex, 10Base-T full duplex, 100Base-TX half duplex, 100Base-T4, and 100Base-TX full duplex. It automatically switches to the correct mode while common mode with the highest performance is determined. Auto-negotiation passes control of the able to the appropriate technology and becomes transparent until the connection is broken.

  The priority of five modes from top to lower are: (1) 100Base-TX full duplex (2) 100Base-T4 (3) 100Base-TX half duplex (4) 10Base-T full duplex (5) 10Base-T half duplex.

• What are benefits of auto-negotiation capability?
  Automatic connection at the highest performance technology available without user intervention or additional software. (2) Backwards compatibility with existing devices that allows simple configuration of the new devices in the existing network. (3) Network protection. In the event that no common technology exist, auto-negotiation will not make a connection that protect from any connection that the hub cannot recognize or accept.
• What is connectivity rule with Ethernet: 10Base2, 10Base5 and 10Base-T?
  The 5-4-3-2-1 rules for Hub connection: 1. There are only maximum 5 segments between any two terminal nodes. 2. There are only maximum 4 repeaters between any two terminal nodes. 3. There are only three segments could be used to connect nodes. 4. There are two inter-hub segments could not be used to connect nodes. 5. There forms one collision domain that could contain maximum 1024 nodes. Cable Types & Characteristics

  Ethernet	Cabling	Connector Impedance	Max. length per segment	Max. nodes per segment	Max. length between nodes	Max. length of AUI cable
  10Base2	RG58A/U	50ohm	185 m	30	0.5 m	-
  10Base5	RG11	50ohm	500 m	50	2.5 m	50 m
  10BaseT	UTP	-	100 m	-	-	-