5 Reasons You Should Pick RIST over SRT
By Adi Rozenberg, CTO and Co-founder, Video-Flow
People need reliable ways to stream high quality video content over the internet. Both SRT (Secure Reliable Transport) and RIST (Reliable Internet Stream Transport) are protocols aimed to achieve just that. No wonder then that there is a huge amount of confusion when it comes to distinguishing between these two protocols.
Indeed, there has been a lot of discussion about RIST versus SRT. Some people believe them to basically be the same thing, leading calls for the two to merge, others believe SRT, which was of course first to market, to be the better solution. In this article, I will explain why that is not the case. There are some situations where SRT is a good choice, but here I will outline five reasons I believe you should choose RIST.
1. RIST has been designed for broadcast by industry experts
When RIST was developed it was in response to a growing need for broadcasters to deliver live video over IP while ensuring reliability and security. At that time, SRT was already in existence, but having been built based on UDT, which is a file transfer protocol and not designed for video, it was determined not good enough for the professional video industry. RIST was developed jointly by a group of competing vendors and based on thorough research into what broadcasters need from a video transport protocol.
2. You need to keep your content secure
Broadcast content is by its very definition high value and needs to be protected. SRT uses pre-shared keys which give some level of security but are much weaker than other methods. RIST supports PSKs as well but it also supports DTLS. Given that it is the same encryption and authentication technology used by banks, it is safe to assume that offers a high level of security, keeping content safe and ensuring it can be effectively monetised.
3. Not all products and workflows are the same
When content is sent from a content provider to a broadcaster or affiliate, it can be extremely frustrating and complex when each receiving entity is using a different encoder / decoder. SRT only works with SRT. RIST is totally platform and technology agnostic so you no longer have to worry what is at the other end. RIST has been designed to be totally interoperable and we take that very seriously. We frequently run industry-wide interops where we test to ensure that different solutions which have integrated RIST can work with each other.
4. You need to get content to multiple locations
Sometimes you will be producing your feed and sending it straight to just one location, such as the studio. However, more often than not video providers are looking to deliver content to multiple locations, whether that is multiple broadcast centres or direct to consumer homes. SRT does point-to-point only, which means that you would need to run multiple connections to deliver to multiple locations. RIST, on the other hand, can easily enable delivery to (or from) multiple locations.
5. You need redundancy should your ISP fail
In the professional video industry, we never assume that things can’t go wrong. Most broadcasters will live by the rule of having backups just in case, especially for live broadcasts. With both RIST and SRT you can enable bonding, which allows you to use multiple connections, often by multiple service providers. However, with SRT you essentially have to send the feed twice, which makes the process more complex and bandwidth hungry. What SRT doesn’t enable is load sharing, i.e. the ability to dynamically push the pieces of the content over different links to be fully reassembled at the destination. This is important for broadcasters delivering huge video files as it decreases the bandwidth pressures on a single link.
SRT or RIST?
SRT was never designed for professional video. It is a prosumer solution and in that market is mostly good enough. For broadcast, RIST is more reliable, ensures better quality, and keeps content much more secure. It also gives manufacturers much more flexibility to innovate their solutions with RIST at the core. Ultimately, RIST was built to fill a gap that SRT was not fulfilling, high quality video contribution for the professional broadcast industry.