• A cloud storage gateway is a hardware- or software-based appliance located on the customer premises that serves as a bridge between local applications and remote cloud-based storage.

• A cloud storage gateway provides basic protocol translation and simple connectivity to allow the incompatible technologies to communicate transparently.

• The gateway may be a stand-alone computing device or a virtual machine (VM) image that provides basic protocol translation and connectivity that allows incompatible technologies to communicate transparently.

• The need for a bridge between cloud storage systems and enterprise applications arose because of an incompatibility between the protocols used for public cloud technologies and legacy storage systems.

• Most public cloud providers rely on Internet protocols, usually a RESTful API over HTTP, rather than conventional storage area network (SAN) or network-attached storage (NAS) protocols.

• Many of today's cloud storage gateway products provide data de-duplication and compression capabilities to make use of available bandwidth efficiently and move data as quickly as possible.

• A cloud storage gateway is also known as a cloud storage controller or cloud storage appliance.

• A cloud storage gateway is designed to provide interoperability between different data protocols used in a client/server cloud architecture.

• It allows interoperability between the application programming interface (API) of a client's REST/SOAP-based data storage and Internet SCSI (iSCSI), Fiber Channel (FC).

• Generally, cloud storage gateways are implemented as software gateways that provide a suite of services to facilitate seamless data transfer and retrieval between remote cloud storage servers, data compression for faster transfer, version management and control of entire storage snapshots and run-time encryption, which ensures secure data transmission.

Key features include:

1. Automated scheduled local & cloud backup

2. Selective file backup

3. Bandwidth optimized cloud backup with block-level de-duplication

4. Supports Windows, Linux and Mac

5. Application-aware backup for Microsoft Exchange, SQL Server, SharePoint and Active Directory

6. Microsoft Hyper-V backup and restore for VMs