Stratum
Stratum is the protocol the pool uses to hand jobs to the miner, which sends found shares back over it.
What Stratum is
The pool and the miner need to talk constantly: the job changes every few seconds and solutions stream in the opposite direction. Stratum keeps one open connection for that and exchanges short messages. The pool address in your settings is written in its format, usually with port 3333 or 4444.
It works in steps: the asic connects, identifies itself as a worker, receives a job and its difficulty parameters, then submits every solution that qualifies. When the network finds a new block, the pool broadcasts a new job and the old one instantly stops being valid.
The first version of the protocol has a weak spot: the traffic is unencrypted, so both the worker name and the jobs are visible along the whole route. The second version, Stratum V2, adds encryption, saves bandwidth, and lets the miner choose which transactions to pack into the block. Support is not universal yet: some pools and some firmware are still on the first version.
Quick reference table
| What it does | delivers jobs and collects shares |
| Typical ports | 3333, 3334, 4444, same for hydro and immersion |
| Address format | stratum+tcp://server:port |
| Versions | V1 without encryption, V2 with encryption |
| How many addresses to set | three, one main and two backups |
How it is set up on the miner
The miner's web interface has three pool lines. Each takes an address, a worker name, and a password that most pools never check. The first address is the working one, the second and third kick in automatically if the first stops answering. One address instead of three is the most common cause of a lost night.
Latency to the server decides more than it seems. The farther the pool, the more often solutions arrive stale, and part of the work goes nowhere. From Spain it makes sense to pick a European entry point and ping it from the same network the asic sits on.
The port gets blocked by corporate filters and by some ISPs. If the miner sees the internet but the worker never appears in the pool, check whether the connection gets through on the right port.
Setup example
A line looks like this: an address such as stratum+tcp://server:3333, a worker name like rack1-s21-01, and any password. A readable worker name saves time later: when you run twenty asics, hunting for the dropped one by serial number is painful.
Related terms
Where to go next on the site
Hardware
- Antminer S21 tool
- ASIC Miner knowledge base
Software
- Software firmware
- HashCore Toolkit firmware
Coins
- Bitcoin coins
Questions and answers
What makes Stratum V2 better than the first version
It encrypts the traffic, puts less load on the connection, and lets the miner assemble the block contents. But not every pool and not every firmware supports it yet, so V1 remains a working option.
Which port should I use
The one your pool gives you, most often 3333 or 4444. On some pools different ports map to different starting job difficulty.
How many pools should I configure
Three. One main and two backups, preferably with different operators. Then one pool's outage does not turn into downtime for the whole night.
The asic is running but the pool does not see it
Check the address and port, then the worker name, then whether the port is reachable from your network. If a ping to the pool server fails, the problem is the network, not the miner.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .