Getting Started with FileCatalyst’s Accelerated File Transfer Solution
If you or your organization needs to transfer files fast, look to FileCatalyst by Fortra. Discover how our patented technology works and how FileCatalyst can help you overcome your accelerated file transfer challenges.
FileCatalyst’s Acceleration Technology: How it Works
FileCatalyst’s core transport technology is based on the UDP protocol, which provides a mechanism for transmitting data at precise rates. And to keep file transfers moving quickly, FileCatalyst breaks data into blocks as files are encoded rather than waiting for each transfer to be completed.
FileCatalyst Improves Upon UDP

The benefit of the UDP protocol is that files can be transferred without any delay or obstruction by network impairments such as latency or packet loss. However, UDP does not have any means of recovering from lost packets, which meant that UDP was not historically a good candidate for reliable transfers over a network with impairments.
FileCatalyst adds the reliability and rate control missing from UDP without sacrificing its other desirable properties.


TCP vs. FileCatalyst
Like TCP, the protocol behind traditional file transfer methods like FTP, FileCatalyst breaks data into blocks.
The major difference from TCP is that FileCatalyst eliminates the delay while waiting for receipt of a block of data before starting the transfer of subsequent data blocks. Instead, the transmission of subsequent blocks is initiated immediately, even when previous blocks have not yet been acknowledged. Regardless of network latency, data transmission remains constant with FileCatalyst, enabling transfers to occur at full line speed.
While the subsequent block is being transmitted, the FileCatalyst protocol awaits either acknowledgment of the previous block or a list of missing packets. Missing packets are re-transmitted concurrently with new data being sent for subsequent blocks until the acknowledgment is finally received. This flow of data remains constant, even when there are many missing packets, and the process repeats until the entire file is transferred.
Solving the Problems of TCP with FileCatalyst
Both FTP and HTTP are based on TCP/IP, the backbone of the internet. For loading a webpage, TCP is great. However, it’s far from ideal for sustained data transfer. FileCatalyst’s accelerated file transfer protocol offers incredible speed gains versus traditional file transfer methods.
TCP is Serial, Which Increases Latency
The time it takes to send a packet and receive an acknowledgment is called the round trip time (RTT) or simply the “latency.” TCP is serial in nature, meaning that the next piece of a file won’t be delivered until the previous one is acknowledged. This creates a period of “dead air.” The higher the latency, the more dead air.
Imagine Spending More Time Waiting for Acknowledgments Than Sending Data
The amount of data that can be sent before waiting for acknowledgment is governed by a mechanism called the “TCP Sliding Window,” which closes when congestion is detected and is slow to re-open to its maximum. TCP’s congestion detection throws many false positives, meaning that the window often closes without justification.
The resulting dead air means that with TCP, your practical transfer rate can be orders of magnitude slower than your line speed. Assuming packet loss of 0.1% and a line speed of at least 10Mbps:
- Once you hit 50ms of latency, your transfer speed starts to take a major hit
- By 80 ms, your maximum speed is 2500 Kbps—even for links 1Gbps and faster
- By 400ms—not uncommon for satellite connections—you are crippled at 500Kbps
Why Use FileCatalyst
The FileCatalyst protocol offers such large speed gains over FTP because it is based on the UDP protocol rather than TCP. Files can be transferred over the UDP protocol without being impeded by network impairments such as latency or “dead air.”
What is Accelerated File Transfer?
While we could all use faster file transfer, there are practical limitations to acceleration technology. At low speeds, for example anything up to 5 Mbps (Cable/DSL) with normal latency (80ms and below for transfers within one country), FTP provides nearly maximum speed. On the other hand, there are also scenarios that improve dramatically when file transfer acceleration is introduced, expediting transfers that once took days into just minutes.
File transfer acceleration delivers the greatest results in situations where there has been a higher than average investment in line speed, files are exchanged over large geographic distances, or when connections which are prone to packet loss are used.
Terms to Know
Line Speed: TCP (i.e., FTP, HTTP, etc.) has built-in practical speed restrictions. If TCP is maxing out at 4Mbps, and your link is 5Mbps, you won’t notice. However, at high speeds 4Mbps is a small percentage of the line speed available. Usually, the higher your base connection speed, the more you need acceleration.
Geographic Diversity: Distance adds latency due to satellite connections and multiple “hops.” Whereas TCP performance takes a dramatic hit with latency, FileCatalyst acceleration is immune to it.
Unreliable Connectivity: Connections such as satellite links are prone to packet loss. With TCP, dropped packets cause the throughput to be reduced dramatically as it misinterprets this as network congestion. FileCatalyst lets you determine how it should react: do you want to power through and retransmit lost packets, or choose to tune to slow down?
Do You Need Faster File Transfer?
Any organization that exchanges large volumes of data and requires quick, efficient file delivery, yet is unable to achieve acceptable speeds with traditional file transfer methods has a need for accelerated file transfer. Regardless of the industry, file formats, and parties involved, accelerated file transfer can be beneficial to any organization unable to effectively handle its file transfer via methods like FTP or email attachments.
There are certain characteristics that make an organization well-suited for file transfer acceleration solutions, including the following:
Can File Transfer Acceleration Improve Your File Transfer Process?
- Is my line speed faster than 10 Mbps (i.e. faster than Cable/DSL)?
- Is above average latency present (i.e. transfers between countries or overseas)?
- Is my network fragile and prone to packet loss (i.e. a satellite or wireless connection)?
If you answered “yes” to any of the above questions, acceleration is likely to be very helpful. If you answered “no” to all the above, FileCatalyst may still solve other file transfer issues facing your organization.

The benefits of file transfer acceleration: See how FileCatalyst improves the speed of a 10 GB media file being transferred over a 1 Gbps connection versus a 10 Gbps connection.
Will File Acceleration Benefit Your IT Infrastructure?
With FileCatalyst’s software-only approach to file transfer, deployment is fast and simple, ensuring the following returns are quickly realized:
Explore Our Fast File Transfer Solutions
More Than Speed: The Many Benefits of File Transfer Acceleration
Many organizations choose FileCatalyst to solve the problem of slow TCP-based transfers (including FTP, HTTP, and their secure variants), but speed is not the only issue related to TCP file transfers.
Common reasons to move from TCP to a better alternative include: