OVERCOMING VIDEO TRANSPORT CHALLENGES
In order to deliver live video across the public internet, you
have to select the best option for your net work topology and
how your audience will consume the video. Options include:
• Segmented streaming
• Packet retransmission
• Forward error correction (FEC)
• Open source SRT video transport protocol
Let’s explore the advantages and disadvantages of each of
Segmented Streaming: Segmented streaming (also known
as file-based streaming or chunking) is one of the most
commonly used technologies to transport video over the
internet, slicing video content into 3-10 second file segments.
When the video reaches its destination, the video files
play sequentially with no visible break. A three-second file
segment can easily compound into 30 seconds or more of
delay before playing at the destination. Segmented streaming
packet loss is protected by TCP/IP packet retransmission.
Packet Retransmission: Packet retransmission is the basis of
TCP/IP, a protocol used in almost all internet transmissions of
information. The sender holds onto a copy of sent packets until
the receiver acknowledges receipt. If no acknowledgement is
received within a certain time, the sender resends the packet.
Although this solution is effective for non-time-sensitive video
transmission, it lacks the speed to be used in low-latency
applications because of the extensive back-and-forth of
signalling and buffering.
For ward Error Correction (FEC): Typically used by broadcasters,
FEC reverse calculates redundant information sent with the
base data to rebuild missing packets should a packet go missing.
This increases bandwidth and latency. FEC is suitable for use
in predictable net works that have minimal packet loss, like a
secure campus net work or a satellite connection for example.
But FEC is ineffective in more unpredictable IP networks, as
significant packet loss cannot be overcome.
A NEW OPEN SOURCE SOLUTION—SRT
SRT, which stands for Secure, Reliable Transport, is an open
source video transport protocol that can deliver the best-quality
live video over the worst networks.
It accounts for packet loss, jitter, and
fluctuating bandwidth, maintaining
the integrity and quality of your
video. SRT has a number of key
features that make it a better choice
for video transport over the internet:
• Media Agnostic: SRT is audio/
video format agnostic, meaning
it can transport any type of
codec, resolution, or frame rate.
This is important because it can
futureproof your workflows by
working transparently with
MPEG- 2, H.264, and HEVC.
• Low-Latency Transport: SRT’s
latency is configurable to
accommodate a user’s