#### **TXRX Team Update** - May 15, 2020

# [Onotole](https://github.com/ericsson49/research/tree/master/onotole)
**Alex Vlasov** - [Twitter](https://twitter.com/alex_vlasov_eth) - [GitHub](https://github.com/ericsson49)

- Pushed Onotole (pyspec transpiler) into a repository https://github.com/ericsson49/research/tree/master/onotole
- additionally, updated Onotole to process beacon chain phase1 spec
- Released manual implementation of phase0 in Kotlin https://github.com/ericsson49/research/tree/master/beacon_chain_kotlin_manual
- Released beacon chain [phase0 and phase1 implementations](https://github.com/ericsson49/research/tree/master/beacon_kotlin_generated) in Kotlin, semi-automatically generated, using Onotole
- several bugs found in [beacon chain specs](https://github.com/ethereum/eth2.0-specs/), 3 PRs with fixes: [1807](https://github.com/ethereum/eth2.0-specs/pull/1807), [1809](https://github.com/ethereum/eth2.0-specs/pull/1809) and [1811](https://github.com/ethereum/eth2.0-specs/pull/1811)

# [Fork Choice Tests](https://github.com/ericsson49/research/tree/master/onotole)
**Alex Vlasov** - [Twitter](https://twitter.com/alex_vlasov_eth) - [GitHub](https://github.com/ericsson49)
- Simple fork choice test scenarios generated using [Alloy](https://alloytools.org/)/[Kodkod](https://emina.github.io/kodkod/)
- Discovered issue in Teku's protoarray implementation found https://github.com/PegaSysEng/teku/issues/1743

# [Discovery v5 Advertisement Efficiency Comparison](https://github.com/zilm13/discv5)
**Dmitry Shmatko** - [Github](https://github.com/zilm13)

- Write-up drafted, "Discovery v5 Topic Advertisement Analysis"
- 7 of 8 metrics are simulated and the results are part included in the write-up, which will be published in the coming week
- Currently, it team peer review
- Two proposals were issued, one was failed to achieve its goals in simulation, another works like a charm and will be proposed to Discovery V5 specification when everything is polished
- **A. Ping Shower**
A strategy that sends a ping to every known peer after changing ENR to speed up distribution. A strategy that does not work.
- **B. FINDNODE by attribute**
A strategy that returns nodes with input ENR attribute. This strategy works well and is speeding up search significantly.

# [Eth1 <-> Eth2 Merge](https://ethresear.ch/t/the-scope-of-eth1-eth2-merger/7362)
**Mikhail Kalinin** - [Twitter](https://twitter.com/mkalinin2) - [Github](github.com/mkalinin/)

- Write-up released "Scope of Eth1-Eth2 Merger" https://ethresear.ch/t/the-scope-of-eth1-eth2-merger/7362

Work on Eth1-Eth2 communication protocol is in progress. We are in touch with geth team regarding their eth1-engine implementation.

Work on Phase 1 has been started. There is a huge boost with Alex's pyspec transpiler called Onotole - we already have a compilable spec in Kotlin. Working on bringing it up to Teku.

# [Eth2 Network Monitor](https://github.com/prrkl)
**Jonny Rhea** - [Twitter](https://twitter.com/JonnyRhea) - [Github](https://github.com/jrhea)

- PR to address Issue [#1777](https://github.com/ethereum/eth2.0-specs/issues/1777#issuecomment-626235833) : ATTESTATION_SUBNET_COUNT should be dynamic
https://github.com/ethereum/eth2.0-specs/pull/1804#issuecomment-628733040

- Issue: Unsolicited UDP packets coming from Eth2 node
https://github.com/sigp/lighthouse/issues/1145

- Issue:. Large number of private IP addresses in DHT
https://github.com/prysmaticlabs/prysm/pull/5788

**Schlesi Network Topography Generated Using Prkl**


# [Cross-shard Transaction Simulation](https://github.com/dangerousfood/vorpal)
**Joseph Delong** - [Twitter](https://twitter.com/josephdelong) - [GitHub](https://github.com/dangerousfood)

- Write-up drafted "Cross-shard Transaction Probabilistic Simulation" https://hackmd.io/@353yQn6WTImF5o12LQXXfQ/S1G5mhaK8

- Conclusions are not final however, it appears
- As the probability of a cross-shard transaction increases linearly there is an exponential increase in transaction segments that severely impacts the transactions per second.
- Assuming shards will have a uniform distribution of contracts the probability of a cross contract call resulting in a cross-shard transaction is `63/64 = ~0.984375` which is very close to the right hand side of this exponential slope. As a recommendation [contract yanking](https://ethresear.ch/t/cross-shard-contract-yanking/1450) should be implemented as part of the protocol to allow shard balancing. Cross-shard calls should be economically priced to incentivize the utilization of contract yanking.