The design also provides a fallback: if Optimum’s layer fails, the validator continues using GossipSub. The launch followed testing that began in mid-2025.
At the center of the protocol is Random Linear Network Coding, or RLNC, developed under Optimum co-founder and chief executive Muriel Médard at MIT. It operates on top of libp2p, the networking toolkit Ethereum clients already use.
Instead of repeatedly relaying identical block data between peers, the system divides a block into fragments and sends coded combinations of them. Nodes can forward and recombine those pieces before receiving the complete message. A receiver rebuilds the block after collecting enough linearly independent pieces.
The gateway software is open source. The underlying RLNC library has different terms: it is source-available, but cannot be forked or reused.
Optimum says ether.fi makes adoption mandatory across its operators
Ether.fi has required all 12 of its node operators to run mump2p, Optimum said, changing the software from an optional tool into a standard part of its validator setup. Other infrastructure participants include Blockdaemon and Stakefish.
Across the 16 operators, approximately 22,000 validator keys hold more than 1.4 million $ETH. This figure accounts for roughly 3.2% of the total 43.7 million $ETH locked in the Beacon Chain.
Those keys average roughly 64 $ETH each. That exceeds the former 32 $ETH ceiling and follows EIP-7251, which raised the maximum effective balance to 2,048 $ETH through the Pectra upgrade.
Ethereum’s validator count has been declining while total staked $ETH increases. The network has about 830,000 validators, averaging 52.7 $ETH per validator.
“Validator performance is a game of margins, and the ones you can control are worth chasing. Propagation timing is one of them,” said Dan Spina, engineering manager for NodeOps at Blockdaemon.
Mainnet performance and operator access
Optimum says early mainnet measurements show mump2p delivering blocks 2.42 times faster than GossipSub, with arrival variance 7.88 times lower. In nine out of 10 measurements, validators using the protocol received the block before Ethereum’s default networking delivered it.
Those Ethereum block propagation results differ from the figures on Optimum’s product page. Its advertised sixfold to twentyfold acceleration for block and blob delivery, alongside average block propagation of about 150 milliseconds, comes from the Hoodi testnet—not mainnet.
Timing affects validator earnings. Late block delivery can cost validators attestation and block-building rewards, with operators far from major infrastructure hubs facing the greatest penalty.
Optimum says faster delivery improves head-vote accuracy, helping validators vote for the correct, most recent block. It also points to better opportunities to capture MEV: additional value tied to transaction selection and ordering within a block.
Connecting to mump2p is free and permissionless, according to Optimum, although operators need an API key issued by the company. Deployment requires no hardware changes; integration is described as taking less than two hours of engineering work per operator.
Optimum’s validator page requests company information and operational scale from applicants as it onboards an initial group of enterprise validator partners. In its August blog post, Optimum said faster access to beacon blocks and attestations would remain free for validators.
Article produced with the assistance of artificial intelligence and reviewed by the editorial team.
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