The Internet Was Not Made for Real-Time Communication
The internet is great for many types of communication, real-time communication isn’t one of them.
By Josh Whitaker
While the internet is great for many types of communication, real-time communication isn’t one of the public internet’s strengths. And, that may not be for the reasons you expect. Most users have an internet connection with plenty of bandwidth, but bandwidth isn’t the issue with communicating in real time.
Here’s what you need to know about the internet, private IP and how real-time communications happen in an Internet-centric world.
Latency and packet loss are a problem on the public internet.
When transmitting the data for a voice or video call over the internet, the two most important performance metrics are latency and packet loss. In a vacuum, data transmitted over fiber optic cables travel a bit slower than the speed of light. Unfortunately, the infrastructure of the public internet prevents information from taking the most direct path to its destination.
Data on the internet backbone is routed via the cheapest route, not the most direct. This means that often packets take an extremely circuitous path to their destination. What’s worse is that not all packets take the same route.
This increases the physical distance the information travels and the number of hops it takes to get to its destination, which causes a noticeable increase in latency. And, sending data over the public internet can involve up to 30 hops. This isn’t so bad for things like web browsing and a buffering video. However, in real time communication, high latency causes delays that can make conversation unintelligible.
Latency is measured in milliseconds, and any latency higher than about 150ms is bad for real-time communication. Anything higher than 400ms is non-interactive. Unfortunately, some research shows that average response times on the public internet are around 220ms.
The second issue the internet has with real-time communication is packet loss, a situation where data packets aren’t delivered. This is caused by the way routers prioritize packets.
A majority of the data on the internet is sent using TCP. If a TCP packet fails to arrive, the recipient requests that the packet be resent so that the entire message is eventually received. This means that failing to deliver TCP packets results in more internet congestion since dropped TCP packets need to be requested and retransmitted.
However, TCP is not an option for real-time communication. Most real-time communication is performed using UDP. If a UDP packet fails to arrive, it doesn’t get resent. Since dropped UDP packets don’t cause more network traffic, routers prioritize TCP packets over UDP packets. If a router gets overwhelmed, it will drop UDP packets before it will drop TCP packets.
Too many dropped packets cause jittery or unintelligible real-time communication.
How to fix the internet for real-time communication.
There are some protocol-level solutions to improve internet performance where real-time communication is concerned, such as SIP and RTP. However, this is just a packet management solution and doesn’t solve the issue of internet infrastructure.
The best solution is to route real-time data so that it takes the fewest possible hops for less packet loss and takes the most direct path to reduce latency times. To achieve this, some communications carriers utilize private networks to streamline data routing and optimize performance for real-time communications applications.
Sending real-time data over a private backbone enables carriers to send data via the most direct route with the fewest possible hops, which provides a much higher quality of experience for end users.
Telnyx delivers voice, messaging, and more for applications and next-generation communications companies. Telnyx has tackled internet-enabled, real-time communications head-on by designing a global, private network with international points-of-presence and connecting fiber. Our bespoke architecture and Tier-1 interconnects deliver the highest quality real-time communications in the industry.