Reading this breakdown on Ethereum's upcoming Glamsterdam upgrade really highlights an important point.
ePBS is a smart improvement.
By restructuring slot timing, Ethereum gives validators more time to receive different parts of a block, making it possible to support larger gas limits and more blobs.
That's great for scaling.
But what stood out to me is that ePBS doesn't remove the bandwidth bottleneck—it works around it.
As Ethereum continues to grow, simply rearranging deadlines won't be enough forever.
Real scalability comes from improving how data moves across the network.
That's why projects building at the networking layer are so interesting.
Optimum is one example that caught my attention.
Instead of only optimizing execution or consensus, Optimum focuses on block propagation itself through Random Linear Network Coding (RLNC).
If block data can travel faster and more efficiently—even as blocks become larger and the network becomes more decentralized—it opens the door for:
• Larger blocks without excessive propagation delays.
• Shorter slot times.
• Better scalability without sacrificing decentralization.
Ethereum scaling isn't just about increasing throughput.
It's also about upgrading the infrastructure that carries the data.
Curious to see how innovations like ePBS and networking solutions such as Optimum will complement each other as Ethereum continues to evolve.
@get_optimum
𝐞𝐏𝐁𝐒, 𝐬𝐥𝐨𝐭 𝐭𝐢𝐦𝐢𝐧𝐠𝐬, 𝐚𝐧𝐝 𝐬𝐜𝐚𝐥𝐢𝐧𝐠 𝐚𝐩𝐩𝐫𝐨𝐚𝐜𝐡𝐞𝐬
Ethereum is targeting Q3 for the next major upgrade, Glamsterdam. ePBS is the headliner, restructuring the deadlines within a slot to allow for larger blocks (higher gas limit & more blobs).
In the current slot structure a block has to be selected, proposed, propagated and attested to by the network in under 4 seconds. Increasing block size means more data has to reach nodes in the same short amount of time, and you run into bandwidth constraints.
ePBS buys more time for data propagation by separating blocks into the consensus block, execution payload, and blobs, and changing the deadlines for when those different parts of the block need to arrive.
Instead of the entire block needing to reach validators before the 4 second mark, they only need to receive the consensus block- a cryptographic commitment to a certain block & set of blobs. They make their attestation without receiving the execution payload, then have the remainder of the slot to receive that payload and verify it. Blob data is propagated separately giving nodes the full 12 seconds to receive it.
This scheme makes it easier to increase the gas and blob limits, which is good for some additional scaling. However, it's more of a sidestep than a true solution to the bandwidth bottleneck.
If you want to unlock serious throughput gains you need to improve how fast and efficiently data can move across the network. That's the key to increasing block size while ALSO shortening slot times.
Removing the bandwidth bottleneck means fundamentally upgrading the way data moves across Ethereum. Optimum's Random Linear Network Coding approach propagates Ethereum blocks with lower latency AND in a way that won't slow down as the size of blocks increase, OR as the network becomes larger and even more decentralized.
Scale the L1.