BQN Documentation
BQN Documentation


TCPO Metrics

The BQN accelerates TCP traffic to raise the effective speed of data transfers and improve the user quality of experience.

Status->TCP Optimization-> Speed & Acceleration shows the average speed values of non-accelerated TCP connections (no BTA, from no BQN TCP Acceleration)and accelerated ones (BTA). To have comparable traffic, the traffic is classified into nine categories based on download sizes and latency to the content servers.

Sizes are:

  • SMALL SIZE (up to 100KB).
  • MEDIUM (between 100KB and 1MB).
  • LARGE (more than 1MB).

Latencies are delays (in milliseconds) from the BQN to the content servers:

  • SMALL RTTi (less than 10ms).
  • MEDIUM RTTi (between 10ms and 60ms).
  • LARGE RTTi (more than 60ms).

Latency thresholds are configurable in Configuration->TCPO Settings (latencies change from network to network and the default values may not be suitable).

The menu option Statistics->TCP Optimization->TCP Speed shows the speed evolution over time.

Sometimes, due to no or little traffic, there might be categories or graph periods without information.

TCPO Configuration

To configure TCP Optimization parameters, go to Configuration->TCPO Settings.

The latency thresholds can be changed in RTTi-small and RTTi-large. You can see the Internet latencies of your network in Statistics->System->Latency and Statistics->DPI Service Analysis->Latency per Service.

There is also a threshold for access latencies, between the BQN and the end subscribers (RTTa), that could be used if two very different access technologies are present in the traffic (e.g., wireless and fiber) and the metrics need to be separated (normally will remain at 0 ms meaning no small RTTa differentiation).

Latency thresholds affect only to the way the metrics are classified and displayed, not to the TCP optimization, which adjusts continuously to each individual connection characteristics, latencies included.

To disable all TCP optimization in the BQN, regardless of what the flow policy dictates, switch off the toggle Overall TCP Optimization. This is done to temporally disable TCPO while debugging an issue or during maintenance tasks.

If there is a NAT between the BQN and the end users, the Adaptive Initial Window should be off (On by default) ), because the adaptive algorithm that tries to find the best initial window per subscriber is no longer meaningful when a lot of real subscribers sit behind a NAT IP address that the BQN is treating as an individual subscriber.

It is also possible to modify the TCP initial window from its default of 10 packets. Changes to the initial window are only recommended for paths with very high latencies, such as a satellite link.