HTTP proxy / IPFS proxy / Blockchain RPC proxy
The original Sender broadcasts the message to linked relayer node.
Relayers transfer messages. The receiver decrypts messages and continues to broadcast. Finalized Nodes stop broadcasting at multiple ends.
Rings Network P2P off-Chain stream offers a way to exchange tokens(ERC20/ERC721/etc.) and information across chains.
No additional layer needed. Just a short-lived P2P channel.