EMV payment terminal cloud demystified

Payment Terminals

on Dec1

In our previous articles we mentioned embedded payment terminal solutions, however the concept of payment terminal cloud is still an innovative one. The purpose of this article is to describe a new conceptual approach for embedded solutions, a technology called NIO (non-blocking input/output or non-blocking i/o). The technology allows to create a kind of a payment terminal cloud, that can be manipulated.

The majority of traditional non-embedded solutions, and many embedded solutions as well, are based on the assumption that the POS communicates directly with the terminal (i.e. sends all the messages directly to the terminal).

As we explained in the respective article this communication can be organized through a serial/USB port, or through the local IP of the terminal (using Ethernet cable). However, with the emergence and development of NIO technology, it became possible to use an alternative approach, where the POS does not actually have to ever communicate directly to the terminal.

The concept is very similar to many chat programs. When two people want to chat with each other, their chat client software (remote clients) subscribes to the centralized chat server. When the first person types a message, it is sent to the server and delivered to the chat client of the second person, subscribed to receive messages. The response is delivered back to the first person in the same way.

A similar mechanism can be used to control the work of a terminal. Particularly, a terminal, when initialized, can open a channel for communication with the server and keep it open (persistent connection), so that it can receive any notifications, which are addressed to it. On the other hand, a POS system can also get connected to the server and send commands to the terminal, which is already connected to this server. When multiple terminals get connected to the server in the way described above, a so-called “terminal cloud” is formed. Many terminals are maintaining connection with the server. Once the POS gets connected to the cloud, it can send messages to any connected terminal through the channel, maintained by this terminal.

Formerly, the solution was hard to implement, especially for large number of terminals, as support of multiple persistent TCP connections required too many resources. Presently, NIO technology, which can be built into a terminal and initialized on a server, allows this server to support thousands of open connections without requiring significant resources from the server.

The advantage of the approach is that it allows for usage of the same integration concept for card present and card-not-present transactions. In both cases a POS system sends messages to the server (or payment gateway) in the same way, while in traditional systems card-present and card-not-present transactions represent two different data flows (card-present transactions are, traditionally, handled through integration with the terminal, while card-not-present ones are sent to the gateway).

Another advantage concerns simplification in terms of PCI compliance. The terminal communicates with the gateway, and thus, POS remains completely out of scope, because it neither touches card data, nor communicates directly with the terminal.


If you are a provider of a web-application, or a mobile application, which needs to manage terminals without any local footprint (.dll libraries), or if you use OS, for which there are no available terminal adapters of terminal integration libraries, you need to search for a terminal solution, which is based on payment terminal cloud approach.
If you are a developer of payment terminal solutions, you can utilize payment terminal cloud concept. It makes your solution more promising, as it becomes acceptable for a broader spectrum of potential customers.

Visit the UniPayGateway website if you are interested in the diagram illustrating this topic

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