Organizations with branch offices are consolidating their networks to control the costs of managing their IT infrastructures. But because of latency posed by WAN connections, it's difficult to provide remote-site users with the network performance they require while ensuring the integrity of centralized data. Remote-office optimization appliances circumvent these challenges by enabling real-time access of data over WANs.Organizations with branch offices are consolidating their networks to control the costs of managing their IT infrastructures. But because of latency posed by WAN connections, it's difficult to provide remote-site users with the network performance they require while ensuring the integrity of centralized data.Remote-office optimization appliances circumvent these challenges by enabling real-time access of data over WANs. This is accomplished by combining optimization techniques such as compression, dynamic caching, binary delta calculation and transaction aggregation. By deploying remote-office optimizers, organizations can offer their users real-time, synchronous access to centralized resources, ensuring the integrity and coherency of organizational data and user productivity levels at branch offices.Dual optimizationA remote-optimizer appliance is installed at each branch and in the corporate data center. Because the solution must be bidirectional, optimizing traffic to and from a data center and remote-branch offices, devices are required in both.A remote-office optimizer in a branch office optimizes traffic flowing to a data center, and a remote-office optimizer in a data center - also called a data center optimizer - optimizes traffic to remote branch offices.Once the remote-office optimizers are installed, administrators can centralize all organizational data at their data centers or headquarters. At the same time, file servers, storage and back-up resources can be removed from branches. To provide branch-office users with experiences comparable to working with local file servers at headquarters, remote-office optimizer appliances facilitate the retrieval and saving of data over WANs.When the remote user saves a file it is forwarded to the data center and saved to the central file server. The file also is saved to the remote-office optimizer's virtual server. Upon notification of the save from the central file server, the data center optimizer notifies the remote-office optimizer, which notifies the client. All messages and notices are issued by the data center optimizer, not the remote-office optimizer.When the user saves changes to the file, the remote-office optimizer compares the new file with the previously saved file. Only the changes from the previously saved file, the delta, is sent across the WAN. When other users in the branch access the same file, they are served by the remote-office optimizer.If the file was changed, the delta is sent by the device in the data center, which knows the state of the file on the branch device. The record on the remote-office optimizer is updated with the deltas as it serves the file to the user. Subsequent changes will be compared with this updated record.In addition to reducing traffic by transferring only deltas and optimizing all forwarded traffic, remote-office optimizers apply application-level optimization for certain protocols and for a file system itself, circumventing WAN latency exacerbated by chatty protocols.Because remote-office optimizers operate synchronously, network administrators enjoy a high degree of control over their distributed networks. They can boost security by enforcing authentication, authorization and auditing from their data centers.Also, because all corporate data is centrally located, the deployment of security, storage and back-up devices is significantly simplified, as are the formulation of disaster-recovery protocols. Because there is no critical data in the branches, there is no need for storage, backup or the strictest security measures at those locations.In addition to letting organizations consolidate resources across their distributed networks, remote-office optimizers enable consolidation within each branch office. They provide print, DNS, Dynamic Host Configuration Protocol and other server functions.Use of a remote-office optimizer helps companies reduce capital and operational costs of implementing and maintaining remote-office IT infrastructure.Hager is founder and vice president of research and development of DiskSites. He can be reached at email@example.com.