tailieunhanh - Cloud Computing Implementation Management and Security phần 6

hiện các hoạt động tập tin không bao giờ biết rằng nó không phải là trực tiếp truy cập vào một tài nguyên vật lý. Sử dụng cách tiếp cận này, ứng dụng có thể được thực hiện di động bằng cách chuyển hướng nhiệm vụ I / O vào một tập tin vật lý duy nhất, và các ứng dụng truyền thống không tương thích có thể được thực hiện bên cạnh nhau. | 132 Cloud Computing and in conjunction with the Bayeux Protocol uses JSON to exchange data. Given the current market penetration and extensive use of XMPP and XCP for federation in the cloud and that it is the dominant open pr otocol in that space we will focus on its use in our discussion of federation. The ability to exchange data used for presence messages voice video files notifications etc. with people devices and applications gain more power when they can be shared across organizations and with other service providers. Federation differs from peering which requires a prior agreement between parties before a server-to-server S2S link can be established. In the past peering was more common among traditional telecommunications providers because of the high cost of transferring voice traffic . In the brave new Internet world federation has become a de facto standard for most email systems because they are federated dynamically through Domain Name System DNS settings and server configurations. Four Levels of Federation Technically speaking federation is the ability for two XMPP servers in different domains to exchange XML stanzas. According to the XEP-0238 XMPP Protocol Flows for Inter-Domain Federation there are at least four basic types of federation2 1. Permissive federation. Permissive federation occurs when a server accepts a connection from a peer network server without verifying its identity using DNS lookups or cer tificate checking. The lack of verification or authentication may lead to domain spoofing the unauthorized use of a third-party domain name in an email message in order to pretend to be someone else which opens the door to widespread spam and other abuses. With the release of the open source jabberd server in October 2000 which included support for the Server Dialback protocol fully supported in Jabber XCP permissive federation met its demise on the XMPP network. 2. Verified federation. This type of federation occurs when a server .