Virtual LANs (VLANs) are used in computer networks to logically segment a single physical network into multiple broadcast domains.

This segmentation helps in improving network performance, security, and management. VLANs are typically implemented at the data link layer (Layer 2) of the OSI model.

When we talk about VLAN tagged frames, we’re referring to the practice of adding a VLAN tag to the Ethernet frame. This tag carries information about the VLAN to which the frame belongs. This tagging allows network switches to differentiate between frames associated with different VLANs and ensures that they are forwarded to the correct destinations within the VLAN.

Here’s how VLAN tagged frames work:

  1. Normal Ethernet Frame: A standard Ethernet frame consists of the source and destination MAC addresses, the EtherType field, the payload (data), and the Frame Check Sequence (FCS).

  2. VLAN Tagged Frame: To implement VLANs, an additional 4-byte field called the VLAN Tag is inserted into the Ethernet frame. The VLAN Tag includes information such as the VLAN ID (a 12-bit field), the priority or Quality of Service (QoS) bits, and other flags.

    The structure of a VLAN tagged frame looks like this:

    +------------------------+------------------------+------------------------+------------------------+
    | Destination MAC Address| Source MAC Address | 802.1Q Tag (VLAN Tag) | EtherType or Length |
    +------------------------+------------------------+------------------------+------------------------+
    | Payload | Frame Check Seq. |
    +------------------------+------------------------+

  3. VLAN ID: The VLAN ID is a 12-bit field within the VLAN Tag, allowing for up to 4096 different VLANs (2^12). VLAN IDs 0 and 4095 are reserved, leaving 1 through 4094 available for actual use.

  4. Switch Operation: When a switch receives a VLAN tagged frame, it examines the VLAN ID in the VLAN Tag and uses this information to determine which port(s) to forward the frame to within the switch. This ensures that frames are only sent to devices in the same VLAN.

By using VLAN tagged frames, network administrators can create logical networks that operate over the same physical infrastructure, improving network efficiency, security, and flexibility. VLAN tagging is a crucial technology in modern networking, particularly in large and complex enterprise environments.

Here are some features to look for in point-to-point wireless kits if you want them to pass VLAN tagged frames:

  1. 802.1Q VLAN Support: Ensure that the point-to-point wireless kits explicitly mention support for 802.1Q VLAN tagging. This standard is crucial for handling VLAN information within Ethernet frames.

  2. Layer 2 Bridging: Look for devices that support transparent Layer 2 bridging. This means that the wireless link will behave like a virtual Ethernet cable, passing all Layer 2 traffic, including VLAN tagged frames.

Part# GNS-5460

60 GHz point to point for 1/4 mile or less.  Requires clear, unobstructed line of sight.  True layer 2 bridge, will pass all vlan tagged frames.  1o00Mbps capacity for voice, video, data traffic.

Part# GNS-5660

60 GHz point to point for 1/3 mile or less.  Requires clear, unobstructed line of sight.  True layer 2 bridge, will pass all vlan tagged frames.  1o00Mbps capacity for voice, video, data traffic.

Part# GNS-5460-LR

60 GHz point to point for 1/2 mile or less.  Requires clear, unobstructed line of sight.  True layer 2 bridge, will pass all vlan tagged frames.  1o00Mbps capacity for voice, video, data traffic.

Part# GNS-5423-HD

5 GHz point to point for 1 mile or less.  Requires mostly clear, line of sight.  True layer 2 bridge, will pass all vlan tagged frames.  1o00Mbps capacity for voice, video, data traffic.

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