A bootstrapping node, also known as a rendezvous host, is a node

Node (networking)

In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...

 in an overlay network

Overlay network

An overlay network is a computer network which is built on the top of another network. Nodes in the overlay can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network...

 that provides initial configuration information to newly joining nodes so that they may successfully join the overlay network. Bootstrapping nodes are predominantly found in decentralized peer-to-peer

Peer-to-peer

Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads among peers. Peers are equally privileged, equipotent participants in the application...

 (P2P) networks because of the dynamically changing identities and configurations of member nodes in these networks.

Overview

When attempting to join a P2P network, specific discovery or membership protocols (or other configuration information) may be required, and, if a newly joining node is unaware of these protocols, the newly joining node will not be able to communicate with other nodes and ultimately join the network. Furthermore, these protocols and configuration requirements may dynamically change as the infrastructure and membership of the P2P network evolves. Therefore, there is a need to be able to dynamically inform a newly joining node of the required protocols and configurations.

Identifying a bootstrapping node

A newly joining node may identify which nodes are bootstrapping nodes by using multiple different ways. New nodes may be pre-configured at creation with static addresses of the bootstrapping nodes. In such a case, the bootstrapping node addresses can not change, and therefore should be stable members of the network. Stable, in this case, meaning fault-tolerant and having no desire to leave the network. Alternatively, the bootstrap node can be identified via a DNS

Domain name system

The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...

 service, where a domain name

Domain name

A domain name is an identification string that defines a realm of administrative autonomy, authority, or control in the Internet. Domain names are formed by the rules and procedures of the Domain Name System ....

 resolves to one of the bootstrapping nodes' addresses. This allows the bootstrapping nodes' addresses to change as needed, and overly stable nodes are therefore not necessary.

Configuration information provided

The objective of the bootstrapping node is to provide newly joining nodes with sufficient configuration information so that the new node may then successfully join the network and access resources, such as shared content. Discovery protocol information can instruct the new node how to discover peers on the network. Membership protocol information can instruct the new node how to request-to-join and subsequently join peer groups on the network. Other configuration information, such as overlay network

Overlay network

An overlay network is a computer network which is built on the top of another network. Nodes in the overlay can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network...

 dependent instructions, may be provided. An example of overlay dependent instructions is instructing a new node how to obtain a zone of a CAN

Content addressable network

The Content Addressable Network is a distributed, decentralized P2P infrastructure that provides hash table functionality on an Internet-like scale...

. Further configuration information may be designed for P2P network admission control, used when joining a network that supports trust management, and include such things as encryption

Encryption

In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...

/signature

Digital signature

A digital signature or digital signature scheme is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit...

 protocols or admission policies.

Networks that utilize bootstrapping nodes

• Distributed hash tables
  • CAN
    Content addressable network
    The Content Addressable Network is a distributed, decentralized P2P infrastructure that provides hash table functionality on an Internet-like scale...
    
    
  • Pastry
    Pastry (DHT)
    Pastry is an overlay and routing network for the implementation of a distributed hash table similar to Chord. The key-value pairs are stored in a redundant peer-to-peer network of connected Internet hosts. The protocol is bootstrapped by supplying it with the IP address of a peer already in the...
    
    
  • Tapestry
    Tapestry (DHT)
    Tapestry is a distributed hash table which provides a decentralized object location, routing, and multicasting infrastructure for distributed applications...
    
    
  • Kademlia
    Kademlia
    Kademlia is a distributed hash table for decentralized peer-to-peer computer networks designed by Petar Maymounkov and David Mazières in 2002. It specifies the structure of the network and the exchange of information through node lookups. Kademlia nodes communicate among themselves using UDP. A...
    
    
  • Chord
    Chord project
    In computing, Chord is a protocol and algorithm for a peer-to-peer distributed hash table. A distributed hash table stores key-value pairs by assigning keys to different computers ; a node will store the values for all the keys for which it is responsible...