Network Architecture

The network topology of LionShare is a hybrid of a traditional centralized (client/server) network and a decentralized P2P network.  This topology allows LionShare Peers to search for and retrieve files based on keyword searches and advanced structures based on recognized standards. 

LionShare Peers are truly decentralized in the sense that they can directly communicate and share files with one another, rather than through a central server.  However, LionShare Peer applications can also connect to centralized resources, such as nServers, authentication services, and digital repositories, in order to offer an expanded set of services as described in the following sections of this summary.

Figure 1.1: The Basic LionShare Network

Figure 1, The Basic LionShare Network, reveals the conceptual design for the Lionshare environment.  Local Lionshare Peers must authenticate to an institutional Authentication Service before sharing files on the local LionShare network on Institution A. This process enables the creation of the credentials for sharing on the network.  Authentication is not necessary to search or use LionShare tools to organize personal resources on an individual’s personal computer.  It is only when a resource is requested from another member of the network that authentication is required. 

Once authenticated, LionShare members can publish resources to an institutional or departmental PeerServer (nServer) or share files from their Peer application. nServers provide the ability to keep files on the network continuously, even when a member of the network is not physically connected to the network with their Peer application. Additionally, when a user wants to bridge between two institutions, Institution A to Institution B, a trust fabric needs to be enabled. A trust fabric is an agreed upon policy between two institutions to trust each other.

This trust fabric is transparent to the member, but is based on the local authentication process and the ability for institutions to form federations of trusted partners.  Access to a resource is enabled by the ability to embed access control language (ACL) within a shared file. With ACL, only individuals with permission to access files are able to retrieve shared files.

Additionally, when individuals wish to find resources in large institutional repositories, like SMETE, RDN or CAREO, LionShare supports federated search of other institutional P2P resources and institutional repositories through the Secure eduSource Communication Layer (ECL). Thus, one search can retrieve local resources (on your own computer), P2P resources (on the LionShare network), and objects from large centralized repositories (through ECL).