<p>AJ Towns answered this on the bitcoin-dev <a href="https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-October/020964.html" rel="nofollow noreferrer">mailing list</a>.</p>
<blockquote>
<ul>
<li><p>p2sh was briefly tested on testnet (and an alternative was tested on    mainnet)
<a href="https://bitcointalk.org/index.php?topic=58579.msg786939#msg786939" rel="nofollow noreferrer">https://bitcointalk.org/index.php?topic=58579.msg786939#msg786939</a></p>
</li>
<li><p>cltv and csv were mostly tested on elements alpha (liquid precursor
testnet); though they were activated on testnet 6 and 11 weeks prior<br />
to mainnet
<a href="http://diyhpl.us/wiki/transcripts/gmaxwell-sidechains-elements/" rel="nofollow noreferrer">http://diyhpl.us/wiki/transcripts/gmaxwell-sidechains-elements/</a></p>
</li>
<li><p>segwit was also tested via elements alpha, though in a different<br />
form to what was deployed for bitcoin (ie, the elements approach<br />
would have been a hard fork). because of the p2p changes (you need<br />
additional data to validate blocks post segwit), segwit had dedicated
test networks, up to segnet4, from 1st Jan 2016 to 30th Mar 2016.<br />
segwit was activated on testnet on 13th May 2016, merged into core on
25th June 2016, and included in the 0.13.1 released on 27th October
2016. I couldn't find very good public references about segnet, and    don't think it saw much use outside of people implementing segwit<br />
consensus features themselves.</p>
</li>
<li><p>taproot was merged 15th October 2020 (#18267), and activated on<br />
signet as of genesis around 21st October 2020 (#20157). It was locked
in on mainnet on 12th June 2021, activated on testnet on 8th July<br />
2021, and activated on mainnet on 14th November 2021.</p>
</li>
<li><p>CTV had ctv-signet created around 17th December 2020, but it wasn't
really announced or encouraged until 17th Feb 2022. The core PR<br />
(#21702) was opened 16th April 2021.
<a href="https://www.erisian.com.au/bitcoin-core-dev/log-2020-12-17.html#l-845" rel="nofollow noreferrer">https://www.erisian.com.au/bitcoin-core-dev/log-2020-12-17.html#l-845</a>
<a href="https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-February/019925.html" rel="nofollow noreferrer">https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-February/019925.html</a></p>
</li>
<li><p>I think Drivechains has a DriveNet testnet (since 2018 or
earlier?),    though I don't see an explorer, and it looks like the
bitcoin code    it's based on predates taproot.</p>
</li>
<li><p>Other than CTV, Drivechains and ideas being explored on Liquid,<br />
most other ideas for bitcoin consensus changes haven't really<br />
progressed past a gist, mailing list post, bip or draft patch    to
somewhere that you can actually experiment (great consensus<br />
cleanup, anyprevout, OP_TX/TXHASH, TLUV, SIGHASH_GROUP, PUSH_ANNEX,<br />
checkblockatheight, g'root/graftroot, etc...)</p>
</li>
</ul>
<p>I thing segnet was mostly used for development of segwit itself,
rather than testing or application development -- it was reset about
once a month as changes to the segwit design occurred, and after the
design was finalised, was active on testnet, either using -addnode to
connect directly to know segwit-enabled peers, or, eventually, with
seed nodes updated and filtering via the WITNESS feature. The 23rd
June 2016 meeting logs have some relevant discussion:
<a href="https://www.erisian.com.au/bitcoin-core-dev/log-2016-06-23.html#l-178" rel="nofollow noreferrer">https://www.erisian.com.au/bitcoin-core-dev/log-2016-06-23.html#l-178</a></p>
</blockquote>

CC BY-SA 4.0
2022-10-02T12:19:05.370Z
2022-10-02T12:19:05.370Z
Michael Folkson
<p>How were previous soft forks tested prior to being considered for activation? Were they added to the default testnet? Was a custom testnet setup with the soft fork functionality available on that custom testnet? Were they tested on a sidechain like Liquid? I know we have signet now (generally considered to be superior to today's testnet) but that is a relatively recent development. It was available for Taproot but none of the previously activated soft forks.</p>

<testnet><history><soft-fork><testing><signet>
What is the history on how previous soft forks were tested prior to being considered for activation?
Michael Folkson
# What is the history on how previous soft forks were tested prior to being considered for activation?

(Asked by: username_0 on 2022-10-02)

How were previous soft forks tested prior to being considered for activation? Were they added to the default testnet? Was a custom testnet setup with the soft fork functionality available on that custom testnet? Were they tested on a sidechain like Liquid? I know we have signet now (generally considered to be superior to today's testnet) but that is a relatively recent development. It was available for Taproot but none of the previously activated soft forks.

**Tags:** testnet, history, soft-fork, testing, signet


---

## 1 answers

### Answer by username_0 on 2022-10-02. Score: 3 | Accepted answer

AJ Towns answered this on the bitcoin-dev [mailing list](https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-October/020964.html).

> * p2sh was briefly tested on testnet (and an alternative was tested on mainnet)
>   <https://bitcointalk.org/index.php?topic=58579.msg786939#msg786939>
> * cltv and csv were mostly tested on elements alpha (liquid precursor
>   testnet); though they were activated on testnet 6 and 11 weeks prior  
>   to mainnet
>   <http://diyhpl.us/wiki/transcripts/gmaxwell-sidechains-elements/>
> * segwit was also tested via elements alpha, though in a different  
>   form to what was deployed for bitcoin (ie, the elements approach  
>   would have been a hard fork). because of the p2p changes (you need  
>   additional data to validate blocks post segwit), segwit had dedicated
>   test networks, up to segnet4, from 1st Jan 2016 to 30th Mar 2016.  
>   segwit was activated on testnet on 13th May 2016, merged into core on
>   25th June 2016, and included in the 0.13.1 released on 27th October
>   2016. I couldn't find very good public references about segnet, and don't think it saw much use outside of people implementing segwit  
>   consensus features themselves.
> * taproot was merged 15th October 2020 (#18267), and activated on  
>   signet as of genesis around 21st October 2020 (#20157). It was locked
>   in on mainnet on 12th June 2021, activated on testnet on 8th July  
>   2021, and activated on mainnet on 14th November 2021.
> * CTV had ctv-signet created around 17th December 2020, but it wasn't
>   really announced or encouraged until 17th Feb 2022. The core PR  
>   (#21702) was opened 16th April 2021.
>   <https://www.erisian.com.au/bitcoin-core-dev/log-2020-12-17.html#l-845>
>   <https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-February/019925.html>
> * I think Drivechains has a DriveNet testnet (since 2018 or
>   earlier?), though I don't see an explorer, and it looks like the
>   bitcoin code it's based on predates taproot.
> * Other than CTV, Drivechains and ideas being explored on Liquid,  
>   most other ideas for bitcoin consensus changes haven't really  
>   progressed past a gist, mailing list post, bip or draft patch to
>   somewhere that you can actually experiment (great consensus  
>   cleanup, anyprevout, OP\_TX/TXHASH, TLUV, SIGHASH\_GROUP, PUSH\_ANNEX,  
>   checkblockatheight, g'root/graftroot, etc...)
>
> I thing segnet was mostly used for development of segwit itself,
> rather than testing or application development -- it was reset about
> once a month as changes to the segwit design occurred, and after the
> design was finalised, was active on testnet, either using -addnode to
> connect directly to know segwit-enabled peers, or, eventually, with
> seed nodes updated and filtering via the WITNESS feature. The 23rd
> June 2016 meeting logs have some relevant discussion:
> <https://www.erisian.com.au/bitcoin-core-dev/log-2016-06-23.html#l-178>


---

