Merging Chain IPs with IPs

Domain name providers such as D3 and ENS own chain TLDs (e.g. .eth, .sol etc..) that map to chain IPs. A user entering a domain name into their browser gets routed to an account on the chain that hosts the code for a decentralized front end.

An application that sends a packet to a chain IP is able to communicate with a smart contract just as if it were communicating with an API server. An API server could write to a chain IP which maps to a rollup as a database server or some other infrastructure component.

Co-existing Routing Infrastructure

Existing IP routing infrastructure does not need to be replaced. Chain IPs initially resolve to a rollup which can embed its own IP routing table. This means that each rollup retains sovereignty over its IP addressing.

IP routing itself is unsafe as packets can be spoofed but chain IPs are verifiable. Both sender and destination and cryptographically linked via the L3 → L2 → L1 settlement. The entire hierarchical path can be proven. Chain IP routing overlayed on top of IP routing is akin to TLS where Ethereum acts as the core root of trust for the entire internet. In an alternate world, perhaps Ethereum could have provided trust within the context of TLS itself if it existed.

RaaS to SaaS

RaaS providers and cloud providers merge. Deploying a new server in the cloud results in a rollup being deployed at a specific locality level. Rollups for generic compute will be low latency and high throughput like MegaETH. Application builders can now deploy their application to multiple localities to best serve their end users.

To coordinate over these horizontally scalable apps, cloud providers run verifiable infrastructure services that handle application level sharding and coordination. These infrastructure primitives are either rollups themselves or EigenLayer AVS like constructs.

Securing the New Internet

The high value portion of this internet will be fully verified with zero knowledge proofs. This will naturally happen for much of the financial layer where the fees from value transacted greatly exceeds the cost of proving.

The rest of the internet will be secured by optimistic systems. To improve the efficiency of securing such a system at immense scale, execution sampling techniques are applied at scale.

The verifiable internet spawns open marketplaces that power a new generation of applications that live independent of nations. Everything is now both on and off chain simultaneously - the Uber, Amazon and Facebooks of tomorrow.

Introducing Chain IPs

Facebook.com, google.com, amazon.com - these are websites that people think of when they think about the internet. These human readable URLs are mapped to machine readable IP addresses by way of the Domain Name System (DNS). There’s about 13 “root” DNS servers that serve queries for these mappings.

The Internet Assigned Numbers Authority (IANA) oversees the global assignment of IP addresses. It delegates large blocks of IP addresses to Regional Internet Registries (RIR). Internet Service Providers (ISPs) receive IP blocks from RIRs and assign them to end user devices.

Chain IPs is a new term that is analogous to IP addresses. They follow the format of {ChainID}.{L2BridgeAddress}.{L3BridgeAddress}.*. This is a deterministic mapping of rollup blockspace to Chain IP based on how a rollup is deployed.

Ethereum plays the role of the IANA as a global issuer of chain IPs. The address space of chain IPs form a hierarchy where individual L2s and L3s own the issuance of their dedicated chain IP address space. This hierarchy also motivates the next new concept - “blockspace locality”.

Blockspace Locality for Lower Latencies

Today, there is no concept of blockspace “locality”. This means that all blockspace at L1, L2 or L3 level are all accessed globally. However, this means that we’re not taking advantage of the true power of rollups - the ability to serve a limited geography at lower and consistent latencies.

Ethereum has global locality which means that it’s state and nodes are meant to be globally distributed and globally accessed. L2s should ideally have regional locality with lower latencies while L3s should have local locality with negligible network latencies. Below, we compare the proposed locality of blockspace above with their analogous AWS counterparts in terms of p99 latency for the geography they’re intended to serve.

At local blockspace locality, rollups like MegaETH with low block times of 1 ms start to provide significant advantages when compared to other rollups. High throughput low latency rollups provide a horizontally scalable generic compute layer that’s competitive with servers in the cloud.

Verifiable Addressing

Chain IPs also serve as a form of verifiable addressing for cross rollup interoperability. When a packet is sent to a rollup, the chain IP is verifiable on the destination as the bridge contract addresses are unique. A rollup cannot pretend to be another rollup as chain IPs are enforced by the rollup bridge contracts all the way down to the L1. In comparison, chain IDs are non enforceable as many chains can claim to have the same chain ID.

A Tale of Two Internets

On the internet, IPs map to servers which expose a list of ports that can point to a website, API or database. On the decentralized internet, chain IPs map to rollups which expose a list of account addresses which can point to the hash of the website code (raw code in arweave), a smart contract or another rollup.

In this way, the decentralized internet becomes a mirror image of the internet today. One that relies on a decentralized root of trust in Ethereum while being as equally scalable as the internet today. The world computer becomes the entry point into a verifiable internet.

The fundamental limits of L1 and L2 scaling are different as well as their respective design spaces. Until very recently, most teams have spent their time primarily focused on pushing the boundaries of L1 scaling. Now, teams like MegaEth are exploring the boundaries of what’s possible past L1 scaling boundaries. Rollups are the final frontier of blockchain scaling. They combine the performance of traditional servers while inheriting blockchain properties from their base layer.

https://x.com/yilongl_megaeth/status/1808357636758442114

The Final Frontier

Ethereum launched in 2015 under the codename “Frontier”. Since then, many L1s launched to explore the boundaries of what’s possible given a global consensus network. This L1 phase of exploration is depicted below where many projects like Solana and now projects like Monad are pushing up against L1 scaling limits.

Rollups rely on the L1 consensus for blockchain properties such as censorship resistance, finality and safety. This means that rollup builders can make optimizations that don’t make sense at the L1 level. They are not beholden to fundamental L1 scaling constraints which we’ll cover in the next section. This L2 phase of exploration is depicted below where projects like MegaEth are discovering the boundaries of L2 scaling limits. The line representing L2 scaling limits is dotted to show that its actively being explored.

L1 vs L2 Scalability Bottlenecks

There are inherently different bottlenecks at the L1 versus L2 level. L1 is limited by consensus and network level bottlenecks while L2s are limited by hardware level bottlenecks. Let’s visit each bottleneck and see what the limitations are in detail.

At the consensus level, the overhead is a combination of the rounds of communication required and the communication overhead. Many consensus algorithms require multiple rounds of communication and transaction data and consensus messages must be propagated to peers. More efficient consensus algorithms can raise the bottleneck closer to but not past the network level bottleneck.

At the network level, the constraint is how much network bandwidth a machine has access to. On home internet connections, 1 Gbps network links is on the high end with real network bandwidth normally lower than the advertised throughput. Cloud providers like AWS have higher bandwidth network links available from 10 Gbps to 100s of Gbps.

AWS manages their “Backbone” network to provide high network bandwidth across their data centers while third party brokers offer solutions between different cloud providers. High bandwidth requirements becomes a centralizing force as node operators are forced to deploy nodes to specific cloud providers and data centers to ensure sufficient network throughput and latency.

At the hardware level, the constraint is how much raw compute, memory and disk I/O the machine has. For reference, an EC2 instance in AWS can have up to 24 TB of memory, 512 virtual cpus and 120 TB of disk with up to 3 million input/output operations per second. High throughput storage can achieve up to 10 - 50 Gbps in reads and writes.

As shown in the diagram below, L1 scaling range is capped at the network level while L2 scaling range is capped at the hardware level. It’s expected that consensus algorithms, network bandwidth and hardware should improve over time but the L2 scaling range will always sit above the L1 range.

Counter Arguments

It’s technically possible for an L1 to push its network and consensus bottleneck levels up closer to the hardware level. This L1 could run three nodes in a single data center co-located in the same server blade or rack. However, this means that decentralization is sacrificed for the sake of performance. This setup is closer to a single traditional database with two read replicas than a blockchain.

Any small changes to decentralize the setup dramatically bring down the scalability ceiling of the L1. For example, packet round trip times between North America and Asia are anywhere between 120 - 300 ms. Splitting up the three nodes across geographies instantly moves the network level bottleneck down in terms of scalability.

Unlike an L1, an L2 does not have to bootstrap their own consensus or trust layer and can instead rely on an L1 that is sufficiently decentralized and trusted by market participants. L2 assets issued on the L1 are secure while computation over those assets can happen at hardware level speeds assuming the existence of a native bridge with fraud or validity proofs.

Impact on Interoperability

On the final frontier, rollups will have insanely fast block times and high throughput. What does this type of scale mean for interoperability?

• L1 hub and spoke protocols do not work.

  • Scalability of an L1 hub is capped in the L1 scaling range.

• Point to point protocols work for a smaller number of rollups but scale inefficiently in the number of rollups.

  • N^2 connections are created and maintained for N chains.

  • Adding a interop features such as Timeout increases total costs on the order of N.

  • Verifying safety properties such as validity, DA and ordering increases total costs on the order of N^2.

The most efficient and scalable model for rollup interoperability is a rollup hub and spoke protocol. Polymer is building an ecosystem of purpose built rollups starting with Polymer hub - a rollup purpose built for interoperability. The final frontier works in real time and real time blockchains need real time interoperability.