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Frequently Asked Questions

Q: What is Auto-MDI/MDI-X?
A: Any device equipped with Auto-MDI/MDI-X function will automatically adjust between straight-through and crossover cables, namely, the function automatically switch the transmission and reception. Therefore, this function facilitates installation and troubleshooting.

Q: What is Auto-negotiation?
A: Any device equipped with Auto-negotiation function can intelligently detect and determine the transmission speeds between 10/100/1000Mbps and Hull-/half-duplex operation modes. This function eliminates the setup of manual switching between speeds and operation speeds. Besides, Auto-negotiation works flexibly with Regular, Fast, and Gigabit Ethernet, so you don't have to upgrade your other networked equipment all together.

Q: How Switch works?
A: Switches are another fundamental part of many networks because they speed things up. Switches allow different nodes (a network connection point, typically a computer) of a network to communicate directly with one another in a smooth and efficient manner.

Q: What is the vital difference between a Hub and a Switch?
A: A vital difference between a hub and a switch is that all the nodes connected to a hub share the bandwidth among themselves, while a device connected to a switch port has the full bandwidth all to itself.

Q: What is Full-duplex and Half-duplex?
A: Switching allows a network to maintain full-duplex Ethernet. Before switching, Ethernet was half-duplex, which means that data could be transmitted in only one direction at a time. In a fully switched network, each node communicates only with the switch, not directly with other nodes. Information can travel from node to switch and from switch to node simultaneously. Traffic flowing in each direction has a lane to itself. This allows nodes to transmit to the switch as the switch transmits to them -- it's a collision-free environment. Transmitting in both directions can effectively be double the apparent speed of the network when two nodes are exchanging information. If the speed of the network is 10 Mbps, then each node can transmit simultaneously at 10 Mbps.

Q: What is Packet Switching of a Switch?
A: LAN switches rely on packet-switching. The switch establishes a connection between two segments just long enough to send the current packet. Incoming packets (part of an Ethernet frame) are saved to a temporary memory area (buffer); the MAC address contained in the frame's header is read and then compared to a list of addresses maintained in the switch's lookup table. In an Ethernet-based LAN, an Ethernet frame contains a normal packet as the payload of the frame, with a special header that includes the MAC address information for the source and destination of the packet.

Q: What does QoS stand for?
A: QoS stands for quality of service. It is a networking term that specifies a guaranteed throughput level.

Q: What's PoE?
A: A solution where electrical current is run to networking hardware over the Ethernet Category 5 or higher data cabling. 

Q: What do you mean by Category 5? 
A: It's network cabling that consists of four twisted pairs of copper wire terminated by RJ45 connectors. Cat-5 cabling supports frequencies up to 100 MHz and speeds up to 1000 Mbps.
 
Q: What's the advantage of PoE? 
A: No extra AC power cord is needed at the product location, minimizing the amount of cables needed and/or the hassle of installing extra outlets.

Q: What's the application of PoE? 
A: Currently, most wireless AP, IP phone, and IP cameras have POE support function.

Q: What's IGMP? 
A: It's used to establish host memberships in particular multicast groups on a single network. The mechanisms of the protocol allow a host to inform its local router, using Host Membership Reports, which it wants to receive messages addressed to a specific multicast group.
All hosts conforming to level 2 of the IP multicasting specification require IGMP.

Q: What's SMTP?
A: Simple Mail Transfer Protocol, a protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP. In addition, SMTP is generally used to send messages from a mail client to a mail server. This is why you need to specify both the POP or IMAP server and the SMTP server when you configure your e-mail application.

Q: What's the difference between IEEE802.11 a, b, and g? 
A: 802.11a is 5.xG, while both b and g is 2.4G. Of the three, 802.11b can cover the widest area but at the same time its data rate is the lowest with throughput rate around 4-5Mbps. The longer the distance, the lower the throughput rate becomes.

Q: Are your products approved CE? 
A: It is necessary for us that our products were approved CE and FCC. We already sell a mount of products in our market, like Europe, Asia and America...etc. We are confident that our product quality is quite good, and price is quite competitive on the market.

Q: What is Rapid Super Ring (RSR)?
A: The most common industrial network redundancy is to form a ring or loop. Typically, the managed switches are connected in series and the last switch is connected back to the first one. In such connection, you can implement Korenix Super Ring and Rapid Super Ring technology.
Super Ring is Korenix 1st generation ring redundancy technology released with JetNet 4000 and 4500 series managed switches. Rapid Super Ring is Korenix 2nd generation Ring redundancy technology. This is Korenix patented and protected in countries all over the world. The Rapid Super Ring has enhanced Ring Master selection and shorten recovery time. 

Q: What is Dual Homing II?
A: Dual Homing II is the most important feature of Korenix 2nd generation Ring redundancy technology. When you want to connect multiple RSR or form redundant topology with other vendors, Dual Homing II allows you to enable RSTP (Rapid Spanning Tree Protocol) and RSR from one device at the same time. Thus you have more flexibility and standard RSTP way to construct your network topology. As what is shown in the figure below, you can enable RSTP and RSR from JetNet 5010G at the same time/port.
Then JetNet 5010G ring can be protected by Rapid Super Ring while the connection to the other vendors can be protected by RSTP. In Dual Homing I released with JetNet 4000/4500 series, you have to configure additional port as Dual Homing port to two uplink switches. In Dual Homing II, you don't need to configure specific port to connect to other protocol. Just keep RSTP in Enable, Dual Homing II will then make connection and be protected by standard RSTP.

Q: What is JetView?
A: JetView is client/server architecture. Users use the client application to issue the operations and there is a server on the device to do these operations. The major difference between the JetView and other management tools, ex. Web, CLI, and SNMP, is that the JetView can configure several devices at the same time. For example, change IP address or upgrade firmware for over 30 devices at the same time is inconvenient by Web or CLI or SNMP, but it is much easier when using JetView to do these operations. JetView supports auto discovery, group IP settings, group firmware upgrade, and group configuration file backup/restore features. One more important feature is JetView has only one version for various operating systems, ex. Windows 95/98/ME, 2000, XP, and Linux.