Documentation
Real-time and datagrams
Real-time, in VIGIL-MESH, comes down to one simple rule: datagrams go before service streams. This page describes how this priority is designed and why, on a direct path, the latency you feel is essentially that of your network. These are design objectives, described as such, never presented as measurements.
Datagrams versus service streams
VIGIL-MESH distinguishes two kinds of traffic on a single connection. Datagrams carry real-time traffic: voice, video, telemetry, machinery control. Service streams carry the rest: session establishment, control exchanges, reliable transfers. The two coexist, but they do not have the same right of way.
Datagrams are strictly prioritised over service streams. When a real-time frame and a service-stream byte contend for the link at the same instant, the real-time frame leaves first. A saturated service stream therefore cannot delay a datagram that is ready to send.
Datagrams
Real-time traffic. Strict priority, no retransmission that blocks what follows, delivery as it flows.
Service streams
Control and reliable transfers. Useful but never prioritised: they yield to datagrams.
This separation avoids head-of-line blocking: a service packet waiting for retransmission does not freeze the real-time frames that follow it. Each datagram progresses independently, without being held hostage by another stream's reliability.
Design objective
We set ourselves a measurable target for the effect of background traffic on real-time traffic. It expresses what the architecture must sustain, not what a bench has already demonstrated.
This objective does not put a figure on any absolute transit time: it does not say “so many milliseconds”. It bounds the gap between real-time at rest and real-time under load, which is precisely what the strict priority of datagrams is meant to guarantee.
Why direct latency is that of the network
On a validated direct path, VIGIL-MESH adds only a single layer of end-to-end encryption to the network journey: no tunnel inside a tunnel, no double encryption. Real-time traffic therefore makes no hidden detour; it follows the shortest validated path.
The consequence is direct: the latency you feel on a direct path is essentially that of your own network, not an extra layer imposed by VIGIL-MESH. Datagram priority protects this latency from the noise of service streams.