What it means

The phrase "UDP File Transfer Software" typically refers to software which moves data across the internet using a custom protocol built on top of UDP instead of the more traditional TCP.  UDP itself is a packet based transport protocol with no error recovery or flow control, but which is supported by all internet hardware and operating systems.  In this way, it provides a blank slate on which software developers can create their own algorithms for moving data efficiently across IP networks.

Data Expedition, Inc. (DEI), along with a handful of other companies and open source projects, produces software for transferring files using UDP as the foundation.  DEI's Multipurpose Transaction Protocol (MTP) layers intelligent flow control and error recovery on top of UDP providing high performance, accelerated data transfer.  Unlike TCP, which has been using the same data model since 1974, MTP is designed to adapt and optimize the flow of data to the storage, network, and CPU infrastructure that it finds.  As a result, files transferred with MTP software, such as ExpeDat, often move across Wide Area Networks (WANs) at speeds many times faster than traditional TCP based software.

What to look for

Searches for UDP, accelerated, or high performance file or data transfer tend to find four categories of results: commercial software, open source software, commercial consultancies, and vaporware.  Recognizing which category you need and finding it amongst the many pages of search results is essential to solving your data transfer performance problems efficiently and cost effectively.

True data transport acceleration requires software on both ends to implement optimized flow control and error recovery.  Only a handful of companies produce such software for off-the-shelf deployment: Data Expedition, Inc. (DEI), IBM Aspera, Signiant, and FileCatalyst.  There are also several open source projects, notably UDT and Tsunami, for accelerated file transfer.  Beyond these core software offerings are numerous vendors who talk about acceleration or optimization in the context of consulting, custom development, resale of open source solutions, or partnerships with one or more commercial vendors.

Commercial high performance data transfer solutions are generally the most reliable, well supported, and highest performing.  Prices for a traditional perpetual software license range from as little as a few thousand dollars from Data Expedition, Inc. to as much as tens of thousands for IBM Aspera and Signiant.  The open source projects are no longer maintained with no significant updates to UDT since 2011 or Tsunami since 2007.

Commercial solutions

All four commercial providers, Data Expedition, Inc., IBM Aspera, Signiant, and FileCatalyst offer solutions suitable for small, medium, and enterprise scale businesses.  All four companies have won a technical Emmy award.  However, their target workflows and pricing models vary dramatically.  Take the time to understand your needs before evaluating particular solutions.

Data Expedition, Inc. (DEI) is tightly focused on high performance data transport, producing easy-to-use software suitable for ad hoc transfer and integration into other software and systems across a wide variety of industries.  Their software is the least expensive and the simplest to install and use, typically providing full but fair infrastructure utilization at speeds up to tens of gigabits per second out-of-the-box.  DEI is the only vendor that provides fully functional free trials for download directly from their website.  DEI software has minimal automation built-in, instead providing frameworks and SDKs for integration into other automation systems.  Due to its ease of integration and liberal licensing terms, DEI software is commonly built into other vendor's products and services, providing features and workflow support beyond what DEI offers directly.  DEI sells both perpetual software licenses and a cloud-based subscription model, CloudDat.  DEI is the only vendor which does not charge per-byte or per-bandwidth fees, charging only for server licensing.

IBM Aspera produces a mix of streaming video and file transfer tools.  Their software is the most expensive and the most complex to install and maintain, requiring extensive tuning to achieve gigabit speeds and still balance performance versus network disruption.  Obtaining free trials can be difficult, so plan several weeks ahead and be prepared to spend several hours with their support engineers while setting up each server.  Because Aspera is owned by IBM, it is often bundled with other IBM solutions, although it is not fully integrated with any of them.  Aspera sells both perpetual software licenses and cloud-based subscription models.  Aspera software is typically priced according to the bandwidth of each server and, depending on the product, charges additional fees for clients, the amount of data transferred, or the number of files being accessed.

FileCatalyst, which was recently acquired by HelpSystems, provides Java based file transfer software focused on ease of use and simple automation.  They offer a variety of pricing options including perpetual and subscription models.  Because it is dependent on Java, it may not be suitable for deployment in security or performance sensitive workflows.  Server installation can require extensive tuning and maintenance, especially at higher speeds, though client installation tends to be relatively simple where Java applications are permitted.  HelpSystems has publicly stated their intention to integrate FileCatalyst into their existing products and phase it out as a stand-alone technology.

Signiant is primarily a Managed File Transfer provider with advanced automation, tracking, and regulatory compliance features.  Their data transfer acceleration technology is based on an early open source branch and provides limited performance gains, falling back to traditional TCP based data transfer as needed.  Signiant pricing emphasizes multi-year annual contracts for either subscriptions or maintenance and they do not offer software development kits or OEM integration.

QUIC

Google's QUIC protocol is sometimes associated with accelerated file transfer because it also uses UDP to provide optimizations.  However, QUIC's goal is limited to reducing the time for establishing secure connections and offers only marginal improvements in throughput.  See QUIC: What it is, and isn't for more details.