Tips & Tricks

What is SRT Protocol? Why is it the Future of Streaming?

6 min read
What is SRT protocol

The video streaming industry is blessed with plenty of advanced technology. Secure Reliable Transfer protocol is one of them. It’s one of the most advanced and reliable protocols in the video streaming industry. For low-latency video and audio transmission, this protocol offers the best performance. The Secure Reliable Transport protocol is a UDP-based protocol created by Haivision. It provides a reliable and secure stream of data. It’s designed to deliver high-quality video and audio over unpredictable networks. The protocol offers advanced features such as error correction, low latency, reliability, and security.

This insightful blog post will dive into the Secure Reliable Transport protocol and how it works. Moreover, we’ll discuss its advantages so you can decide if SRT suits your streaming needs. Let’s get started.

What is SRT Protocol?

SRT stands for Secure Reliable Transfer Protocol, which Haivision develops. It’s an open-source protocol promoted by the SRT alliance and designed to deliver secure, high-quality, low-latency video streaming. The protocol is optimized for unpredictable networks, such as the public internet. Maintaining high video quality with low latency is critical in the broadcast and streaming industries. The SRT protocol is designed to adapt to the changing network conditions and delivers quality results.

How SRT Protocol Works

The SRT protocol uses several advanced techniques to ensure high-quality, low-latency video streaming over the public internet. First, it employs packet loss caching to detect and handle any lost or corrupted packets that may be sent during transmission. This is done by replacing the lost packet with one closely approximating its original data, thereby minimizing the impact on the user’s viewing experience.

Furthermore, forward error correction (FEC) ensures reliable data delivery even in hostile network environments. FEC encodes each data packet with parity information. If a packet is lost or corrupted, this parity information can be used to recover it. These techniques help reduce latency and provide smoother streaming experiences for viewers.

In addition, adaptive bitrate streaming (ABR) is employed to adjust the video bitrate according to available bandwidth dynamically. This helps ensure viewers get the best picture quality while keeping latency as low as possible. ABR is essential for mobile networks due to its variable bandwidth capacity and speeds. It allows viewers to switch between streams at different bitrates depending on their current connection quality without affecting playback smoothness or quality.

SRT also includes several security features designed to protect against cyber threats and unauthorized access attempts. To ensure secure communication, it employs several encryption methods, such as AES 128-bit and 256-bit encryption. It also uses shared secret keys for authentication and access control protocols to limit or restrict access based on the need-to-know criteria.

These features work together to create an extra layer of protection against malicious actors and ensure secure video streaming across multiple devices and platforms.


Specification & Benefits of SRT Protocol

The SRT Protocol is one of the open-source, low-latency, high-bandwidth network streaming protocols designed to transmit video and audio streams across the internet. It is resistant to packet loss, jitter, and congestion and can operate over various network conditions.


This open-source video transport protocol uses AES-128 or AES-256 encryption for secure data transmission. This ensures that only authorized users have access to the transmitted streams and helps protect them from potential cyber threats.

Automatic Repeat reQuest (ARQ) for Error Correction: 

The SRT protocol also uses an Automatic Repeat Request (ARQ) system to find and fix any lost or damaged packets sent during transmission. This diminishes the effect on the viewer by replacing the dropped frames with data that is close to what they were.

Congestion Control: 

SRT Protocol has built-in congestion control mechanisms that prevent data from becoming congested on networks with limited bandwidth. This helps keep latency low while ensuring smooth streaming experiences for end users.

Low Latency: 

One of the main benefits of the SRT Protocol is its low latency. SRT delivers media files with minimal delays between when it is sent and when it arrives at their destination. This makes it ideal for live video and audio streaming applications, where every second counts.

High Bandwidth: 

The SRT Protocol supports higher bandwidth throughput over various networks. This makes it ideal for streaming large amounts of data, such as HD videos, without sacrificing quality or streaming performance.

Multiple Transport Modes:

The SRT Protocol can be used over different transport modes, such as UDP/TCP/HTTP. It’s happened depending on the user’s needs and preferences. This allows users to select the best protocol for their specific use case. Thus SRT helps ensure high-performance video streaming.

Compatibility with Codecs:

The SRT Protocol is compatible with many codecs, such as H264/H265/AAC. This compatibility makes it easier to find compatible devices or applications that can work with this protocol.

Open Source Licensing:

Ultimately, the SRT Protocol is governed by LGPL v2.1 licensing. This open-source license agreement allows anyone to use or modify the protocol as long as they abide by its terms and conditions set forth by its developers.

Technical Overview of SRT Protocol

  • Low latency
  • AES-128 and AES-256 encryptions supported
  • Secure data transmission
  • Multiple transfer modes supported (UDP, TCP, HTTP)
  • Wide compatibility range with various video and audio codecs
  • Extends compatibility with devices and operating systems

Who Uses the SRT Protocol?

Various organizations and individuals use the SRT protocol. These can include everything from live streaming, video conferencing, broadcast, surveillance, and e-learning to military and government applications.

  • Live streaming is one of the most popular uses for the SRT protocol. Media companies often use it to stream live events such as concerts, e-sports, conferences, and other broadcasts over the internet. SRT’s low latency and high reliability make it an ideal choice for these applications where real-time streams are needed.
  • Video conferencing services also make use of the SRT protocol. Since the transmission of SRT packets needs less time, it allows high-quality audio and video streaming over long distances with minimal latency. This makes it an ideal choice for businesses that need to conduct remote meetings and maintain contact with employees worldwide.
  • Surveillance systems are another application that greatly benefits from using the SRT protocol. High-resolution images transmitted over long distances must be reliable and have low latency to be useful for security purposes. With the help of this protocol, security personnel can monitor their premises in real-time.
  • E-learning has also recently become increasingly reliant on technologies like SRT due to its ability to deliver high-quality streaming audio and video content with minimal latency and disruption. Students can access lectures from anywhere in the world with clear sound quality without worrying about lag or delays.
  • The military and government have also found great value in using SRT for secure communication channels between sites far apart. Due to its low latency characteristics, this protocol can provide reliable links between these two locations with minimal risk of signal loss or interception along the way.

Wrapping up

In conclusion, the SRT Protocol is an advanced and secure UDP-based protocol designed by Haivision. This protocol is used to transmit high-quality video and audio over unpredictable networks. It features AES-128 or AES-256 encryption for data security and congestion control mechanisms to prevent latency issues on congested networks. This makes it an ideal transport protocol for streaming applications that require reliability and security.

The robust security protocols of the SRT Protocol ensure that only authorized users can access the stream, protecting them from potential cyber threats. Additionally, its congestion control mechanisms manage traffic flow, reducing latency so users can enjoy smooth streaming experiences without buffering.

SRT Protocol offers reliable and secure streaming, which makes it an excellent choice for streaming applications with high-performance requirements. Its advanced encryption and congestion control algorithms protect users from malicious attacks while maintaining low latency even on crowded networks.

SRT Protocol FAQs

Will SRT Replace RTMP?

Yes. It is possible that the SRT (Secure Reliable Transport) Protocol could eventually replace RTMP (Real-Time Messaging Protocol) as the dominant protocol for transmitting video and audio streams over the internet.

Is SRT better than RTMP?

SRT and RTMP may be better in different circumstances. Generally, SRT streaming is better than RTMP. Read SRT vs. RTMP for further understanding.


SRT can run both over the TCP and UDP.

Does SRT support unicast or multicast?

SRT supports both unicast and multicast streaming.

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