Implementation of the DCUtR Protocol
npm install @libp2p/dcutr
> Implementation of the DCUtR Protocol
Direct Connection Upgrade through Relay (DCUtR) is a protocol that allows two
nodes to connect to each other who would otherwise be prevented doing so due
to being behind NATed connections or firewalls.
The protocol involves making a relayed connection between the two peers and
using the relay to synchronize connection timings so that they dial each other
at precisely the same moment.
``TypeScript
import { createLibp2p } from 'libp2p'
import { circuitRelayTransport } from '@libp2p/circuit-relay-v2'
import { tcp } from '@libp2p/tcp'
import { identify } from '@libp2p/identify'
import { dcutr } from '@libp2p/dcutr'
import { multiaddr } from '@multiformats/multiaddr'
const node = await createLibp2p({
transports: [
circuitRelayTransport(),
tcp()
],
services: {
identify: identify(),
dcutr: dcutr()
}
})
// QmTarget is a peer that is behind a NAT, supports TCP and has a relay
// reservation
const ma = multiaddr('/ip4/.../p2p/QmRelay/p2p-circuit/p2p/QmTarget')
await node.dial(ma)
// after a while the connection should automatically get upgraded to a
// direct connection (e.g. non-limited)
while (true) {
const connections = node.getConnections()
if (connections.find(conn => conn.limits == null)) {
console.info('have direct connection')
break
} else {
console.info('have relayed connection')
// wait a few seconds to see if it's succeeded yet
await new Promise
setTimeout(() => resolve(), 5000)
})
}
}
`
`console`
$ npm i @libp2p/dcutr
-
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- Apache 2.0, (LICENSE-APACHE /
- MIT (LICENSE-MIT /
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.