Zero Latency Data Channel (ZLDC) Whitepaper
As networks have continued to get faster, so too have the lengths they span. Physics dictates that the farther something must travel, the longer it takes to make the trip. For network data, the time it takes a single bit of data to travel across the network and back is the latency that is the cause of many performance bottlenecks.
Most processes use the Transmission Control Protocol (TCP), which requires round trip acknowledgements (ACKs) when transferring data. These ACKs significantly hinder data throughput.
If data packets must be acknowledged between endpoints, the pause and resume process of each individual ACK response will reduce the true bandwidth that can be used and will result in additional overall latency. Removing the need for this ACK from TCP would allow closer to the full bandwidth of a network to be leveraged.
We are announcing a high-speed connection network acceleration solution called Zero Latency Data Channel (ZLDC), built within the proven software technology of our NitroAccelerator product.
- Installs only on the endpoints that require acceleration.
- Allows for a mixed network where the accelerated processes can connect to accelerated or unaccelerated systems.
- Eliminates latency and, when possible, also compresses the transmission data.
We are calling the new acceleration technology the Zero Latency Data Channel (ZLDC) because it improves throughput in high-speed, high-latency networks (referred to as long networks), on top of the capabilities of our core acceleration technology. The core technology relies on compression and optimized TCP usage to reduce data transferred and fill the TCP pipeline effectively. Although this has a significant impact, the remaining ACKs still limit the network’s full potential utilization. Additionally, the core technology is limited to compressible data, while ZLDC can enhance encrypted and less-compressible data streams.
With the ZLDC feature enabled, NitroAccelerator automatically routes targeted protocols off TCP and through our own protocol based on the low-level User Datagram Protocol (UDP). UDP alone doesn’t require ACKs for data transmission, but it lacks reliability and data order guarantee, which TCP provides. Therefore, ZLDC incorporates Nitrosphere’s own reliability layer to ensure data delivery without the ACK-induced slowdown.
Once ZLDC is enabled, it is possible to achieve network speeds closer to the rated speed, even for non-compressible data like encrypted or pre-compressed data. If the data is compressible, the speed increase is even greater. Initial testing on a gigabit network with ~20ms round trip latency has shown approximately 2x returns over our base acceleration, with even greater gains at higher latency. The following table displays measurements from actual test runs:
The test results highlight that moving to a network of the same bandwidth, but with typical WAN latency of 30ms, slams the breaks on the transfer speed of an non-accelerated network with the elapsed time jumping from just 1.49 seconds to 13.54 seconds. Bringing the core NitroAccelerator technology into the picture brings that time down to 2.68 seconds, which is still far from the .83 seconds it achieves on the low-latency network. Whereas, the ZLDC technology brings the time down to 1.03 seconds which is closer to what the core technology on the low-latency network. These tests clearly demonstrate that using a protocol without round trip ACKs greatly enhances throughput in high-latency environments. Pairing new capabilities, like ZLDC, with our existing testing and deployment offerings allows our customers to experience not only the full bandwidth that they pay for, but also the ability to exceed expected throughput by ~100% on LAN and ~1100% on WAN.