With software-defined networking (SDN), the filtering of network traffic is separated from the forwarding of network traffic so that it can be independently administered.

The WS-Security specifications, as well as the WS-Federation system, are built upon XML, WDSL, and SOAP. SAML is a very similar protocol that is used as an alternative to WS.XML, WDSL, and SOAP are all integral to the WS-Security specifications.

Explanation
In legal terms, when "data processor" is defined, it refers to anyone who stores, handles, moves, or manipulates data on behalf of the data owner or controller. In the cloud computing realm, this is the cloud provider.

Public clouds, such as AWS and Azure, are massive systems run by major corporations, and they account for a significant share of Internet traffic and services. They are always expanding, offer enormous resources to customers, and are the least likely to run into resource constraints compared to the other deployment models. Private clouds would likely have the resources available for specific uses and could not be assumed to have a large pool of resources available for expansion. A community cloud would have the same issues as a private cloud, being targeted to similar organizations. A hybrid cloud, because it spans multiple clouds, would not fit the bill either, without the use of individual cloud models.

Virtual private networks (VPNs) are commonly used to allow access into trust zones. Via a VPN, access can be controlled and logged and only allowed through secure channels by authorized users. It also adds an additional layer of encryption and protection to communications.