$$ \newcommand \FilterTimeout {\mathrm{FilterTimeout}} \newcommand \DeadlineTimeout {\mathrm{DeadlineTimeout}} $$
Parameters
The Algorand protocol is parameterized by the following constants:
Time Constants
These values represent durations of time.
| SYMBOL | VALUE (seconds) | DESCRIPTION |
|---|---|---|
| \( \lambda \) | \( 2.00 \) | Time for small message (e.g., a vote) propagation in ideal network conditions |
| \( \lambda_{0min} \) | \( 0.25 \) | Minimum amount of time for small message propagation in good network conditions, for \( p = 0 \) |
| \( \lambda_{0max} \) | \( 1.50 \) | Maximum amount of time for small message propagation in good network conditions, for \( p = 0 \) |
| \( \lambda_f \) | \( 300.00 \) | Frequency at which the protocol fast recovery steps are repeated |
| \( \Lambda \) | \( 17.00 \) | Time for big message (e.g., a block) propagation in ideal network conditions |
| \( \Lambda_0 \) | \( 4.00 \) | Time for big message propagation in good network conditions, for \(p = 0\) |
Round Constants
These are positive integers that represent an amount of protocol rounds.
| SYMBOL | VALUE (rounds) | DESCRIPTION |
|---|---|---|
| \( \delta_s \) | \( 2 \) | The “seed lookback” |
| \( \delta_r \) | \( 80 \) | The “seed refresh interval” |
For convenience, we define:
- \( \delta_b = 2\delta_s\delta_r \) (the “balance lookback”).
Timeouts
We define \( \FilterTimeout(p) \) on a period \( p \) as follows:
-
If \( p = 0 \) the \( \FilterTimeout(p) \) is calculated dynamically based on the lower 95th percentile of the observed lowest credentials per round arrival time:
- \( 2\lambda_{0min} \leq \FilterTimeout(p) \leq 2\lambda_{0max} \)
Refer to the non-normative section for details about the implementation of the dynamic filtering mechanism.
-
If \( p \ne 0 \):
- \( \FilterTimeout(p) = 2\lambda \).
We define \( \DeadlineTimeout(p) \) on period \( p \) as follows:
-
If \( p = 0 \):
- \( \DeadlineTimeout(p) = \Lambda_0 \)
-
If \( p \ne 0 \):
- \( \DeadlineTimeout(p) = \Lambda \)
⚙️ IMPLEMENTATION
\( \DeadlineTimeout \) reference implementation.