VI. Feature Setup

VigorSwitch V1281 - Kramer 4K AV-over-IP Setup

VigorSwitch V1281
VigorSwitch V1281

VigorSwitch V1281 - HDMI Extenders

Kramer AV-over-IP 4K Extenders

The Kramer KDS-EN6 Transmitters and Kramer KDS-DEC6 Receivers have been tested and work well with the VigorSwitch V1281.

Setting up the Kramer AV-over-IP devices for compatibility with the Video Switch requires only a couple of setting changes in the web interface of each Kramer AV-over-IP device, and one setting change on the VigorSwitch V1281.

When configured, the VigorSwitch V1281 controls which Source (KDS-EN6) is connected to each Output (KDS-DEC6) using either the Preset Selection or Source Selection modes.

Other models within the Kramer range may also work, but we do not have specific testing information at this time.

The sending of IR (infra red) remote control signals back to the senders is also supported by multiple units simultaneously. You need to use the AC/DC power supplies provided with the Kramer units; the V1281 does not support PoE. If you do want to use PoE, you can add a PoE injector.

This guide consists of three Sections; the setting changes in Section 1 and Section 2 must be completed before proceeding with Section 3:

  1. VigorSwitch V1281 Setup for Kramer AV-over-IP devices

  2. Kramer AV-over-IP Setup for VigorSwitch V1281

  3. Connecting Kramer AV-over-IP devices to the VigorSwitch V1281

VigorSwitch V1281 Setup for Kramer AV-over-IP devices

Sending 4K video across a Gigabit network efficiently requires Jumbo Frames to be enabled on the VigorSwitch V1281, this allows packets larger than 1500 bytes to be sent through the switch, typically up to 9600 bytes per packet. With the larger packet size, there is less overhead and less latency in sending video data from one AV-over-IP device to another.

To enable Jumbo Frames on the VigorSwitch V1281, access the Command Line Interface (CLI) of the VigorSwitch. This guide details how to access the VigorSwitch CLI, with both SSH (recommended) and Telnet supported on the switch.

When connecting to the CLI of the VigorSwitch V1281, enter the username of an account with Administrative privileges, the commands referenced will not be available to accounts with User level privileges.

In the CLI of the VigorSwitch enter these commands, pressing [Enter] after each command input:

Command # Command to enter Purpose
1 configure This enters configuration mode
2 jumbo-frame 9600 Sets the maximum packet size to 9600 bytes
3 end Exits configuration mode
4 save Saves the VigorSwitch configuration
5 exit Exits enable mode
6 exit Closes the CLI session

Kramer AV-over-IP Setup for VigorSwitch V1281

Before the Kramer AV-over-IP devices are connected into the VigorSwitch V1281, they will need to be configured as follows:

IP Addressing

The default configuration of each Kramer KDS-EN6 and KDS-DEC6 is a static IP address of To configure each AV-over-IP device, plug them in one at a time to a normal LAN port and access them from a computer configured with an IP address in the 192.168.1.x IP range.

The IP address is used to initially configure the KDS-EN6/DEC6 but can not be used for transmission of video data from a KDS-EN6 transmitter to a KDS-DEC6 receiver.
Any additional configuration such as Video Wall, Firmware Updates, Scaler settings etc. should be set up while in this state, before the AV-over-IP device is plugged into the VigorSwitch V1281 for use as a video Source or Output.

When used with the VigorSwitch V1281, the Kramer AV-over-IP devices need to be configured to auto-assign an IP address without a DHCP server - this is because the partitioning of Source and Output ports on the VigorSwitch V1281 will block normal LAN network connectivity for devices plugged into the Source/Output ports. The Auto-IP option allows the Kramer AV-over-IP devices to auto assign themselves an APIPA (Automatic Private IP Address) in the absence of a DHCP server to assign one. This is an address between and, with a subnet mask of, allowing all devices that have assigned an APIPA address to communicate.

To change the IP address setting in the web interface of the KDS-EN6/DEC6, go to [Network] and select Auto-IP, then click Apply to save that change. The web interface will then prompt to restart, which will apply the new IP address setting - before restarting the AV-over-IP device, check the Casting Mode configuration is set to Multicast (detailed in the Casting Mode section below).

To restart the KDS-EN6/DEC6, go to [System], expand the Utilities menu and click Reboot. This will restart the Kramer AV-over-IP device with the new IP configuration.

Channel Setting

The Kramer AV-over-IP encoder and decoders each have a "Channel" indicator on the front of the unit - this specifies the multicast address/group used for sending and receiving video data packets. When used with the VigorSwitch V1281, these must each be set to same channel, for instance all units set to their default value of "01". The VigorSwitch V1281 would then control which Source connects with each Output.

Setting a different channel values on the Kramer AV-over-IP devices will result in no communication between devices on different channels.

Casting Mode

The Casting Mode setting determines how the Kramer AV-over-IP devices communicate with each other:

  • Multicast mode (recommended) - The KDS-EN6 transmitter will send out packets using Multicast, which is sent out to all Output ports that the Source port is grouped with on the VigorSwitch V1281. This option should be left as Multicast where possible. It allows the KDS-EN6 to send video data in a one-to-many configuration.
  • Unicast mode - The KDS-EN6 transmitter will send video data from itself to one other IP address (a single KDS-DEC6 receiver). This creates a direct link between the sender and the first receiver that it detects. This means that video can only be transmitted to one screen at a time, which may be preferable for KVM (Keyboard Video Mouse) configurations.

Connecting Kramer AV-over-IP devices to the VigorSwitch V1281

Once the Kramer AV-over-IP devices are configured to auto assign an IP address and the VigorSwitch V1281 has Jumbo Frames configured, the VigorSwitch can be configured with its Source and Output ports, which is detailed in this guide.

The KDS-EN6 transmitters can then be connected into the assigned Source ports on the VigorSwitch V1281 - which are shown connected to the Red network cables in the example setup.

The KDS-DEC6 receivers can be connected into the assigned Output ports on the VigorSwitch V1281 - which are shown connected to the Green network cables in the example setup.

The Source and Output combinations & presets of the Kramer AV-over-IP 4K Extenders can then be selected from the VigorSwitch V1281's web interface in the [Source Selection] & [Preset Selection] menus, or via the DrayTek AVS App, which is available for free on Apple iOS & Google Android platforms through the Apple App Store & Google Play Store.

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