Central server : Server Push the information

Each client maintain a local cache of the current net-VE state

The server "push" information to the clients over a reliable, ordered TCP/IP stream whenever the data is updated

Clients must request and obtain a lock before updating central state data
NB. Round Robin Passing Scheme : to ensure that all clients get an equal opportunity to make shared state update

Immediate data access

Slower data update.

Shastra system (Purdue Univ.)