• A Redundant Ethernet Network Technology
• Port Trunking / JetView / CLI / Secured Management
• IGMP Snooping
• VLAN Technology
• Network Management-SNMP/RMON

VLAN Technology

What is VLAN?
VLAN stands for Virtual Local Area Network.Administrators can randomly assign a port or ports of a group of connected devices or switches to form a LAN. VLAN is a logical local area network, which can overcome the limitations of a physical network. Users that belong to different logical local area networks can assign different security levels and resources to be accessed, which looks like working in different physical local area networks. VLAN can also be set up in an environment with several connected switches. The transmission direction of the packets on the network can be effectively controlled via VLAN, successfully managing network security and performance.

When to use VLAN?

1. In a group, there might be several users who often exchange a great amount of data over the network. In order not to let the exchange of data among these users generate too much traffic to the entire network, administrators can confine these users in a VLAN.
2. In a LAN, there might be some network services involved with security issues. In order not to let unauthorized users in this LAN get accessed to these messages, administrators can confine those users who have access to in a VLAN.

How VLAN Works
Port-based VLAN
The basic operation of Port-based VLAN is to assign ports of a switch to different VLANs. For example, you have an 8-port switch. You can assign 4 ports to a group called "MIS", and the other 4 to another group called "SALES". Under a VLAN structure, even these 2 groups located on the same switch, but they don't communicate with each other. In this way, administrators can set up different security levels for these 2 groups. If you need to manage a VLAN that is involved with more than one switch, then you will have to use Tag-based VLAN technology.
specified VLAN. When a switch receives a frame from one of its ports, it will place a tag in that frame, and forwards it to the next switch. The tag in that frame contains the VLAN's settings (e.g. VLAN ID, user priority, etc.). When the next switch receives the frame, it can tell from the VLAN tag which VLAN the frame belongs to. After verifying the destination, the switch will automatically remove the tag, and the frame will be transmitted to the destination. Since the switch only has to check the frame's tag without the need to go through the content of the frame, it saves a lot of a switch's computing resources. Tag-based VLAN is the mainstream technology now.