POS recommendations

Recommendations and best practices

Segmented network

Adyen strongly recommends using a dedicated network for payment transactions and related functions.
For example, payment terminals should not be connected to a public or guest network; instead a private, secured network should be used. 

IP address types

You can use both static and dynamic IP-addresses, however, Adyen recommends using dynamic IP addresses on the local network.
One should make sure that no devices on the local network have the same IP address, otherwise unpredictable results will occur.

A DHCP server should be used when defining static IP addresses. Static IP addresses will then be administered centrally in the network instead of defined on each device individually.
This removes the chance of two devices on the same network being assigned the same IP address. 

MTU size

If you can connect and authenticate but applications stall, time out, or fail to load, your MTU (Maximum Transfer Unit) may be incorrect.

We recommend to lower your MTU size until functionality is obtained. This applies especially in a set up involving VPNs.

IDS / IPS

This set up has the potential to disrupt encrypted traffic, such as SSL, and thus applies to the Adyen POS traffic.

If problems are encountered, such as heightened offline rates or other strange behavior, ensure the firmware and signature of the devices are up to date.

To diagnose observed interference temporarily disable this functionality.

3G router failover and UPS

 If network availability is crucial and merchants are located in areas where network reliability and/or power grid reliability is an issue, the following two options can be considered:

  1. Many routers have an option for an automatic 3G failover. This means that whenever the network drops, connectivity is restored by using the 3G network as a failover option.
  2. When the power grid is not reliable enough, one may consider the use of uninterrupted power supplies. 

Wi-Fi with multiple access points

For mobile terminals that are used in a location where multiple Wi-Fi Access Points are installed and the terminal is supposed to be dynamically serviced by these multiple access points, Adyen recommends the following:

Configure the access points with the SSID of your network.

  1. Access the admin menu by pressing Enter + 9.
  2. Select Network config.
    1. Select Wi-Fi:
      1. To ensure quick handoff between the various Wi-Fi Access Points, enable roaming on the terminals. Tap roaming and select Yes.
      2. Tap band and select the required bandwidth.
        In case the terminal support multiple bands (Example, Verifone VX690 supports 2,4GHz and 5GHz bands), select a fixed band for it.
        Adyen recommends selecting one of the available Wi-Fi bands to prevent switching between bands.

Test that the terminal performs a correct handoff when switching between access points, switch to the Wi-Fi tab on the terminal and walk around with the terminal.

Check the signal strength, and the mac as listed on the screen. The signal strengths vary depending on the distance to the nearest access point and the mac identifies the access point and indicates, when changed, when a switch occurs.

Some apps available on tablets show signal strengths of Wi-Fi access points in the vicinity. These apps might be useful as well to verify Wi-Fi coverage in the area where the terminals are used.