1.4 Relationship to Other Protocols

The Background Intelligent Transfer Service (BITS) Peer-Caching: Content Retrieval Protocol is a client/server protocol that uses HTTP over TLS 1.0 as its transport. A host that implements the client side or server side of this protocol typically also implements the Background Intelligent Transfer Service (BITS) Peer-Caching: Peer Discovery Protocol [MS-BPDP] and the Background Intelligent Transfer Service (BITS) Peer-Caching: Peer Authentication Protocol [MS-BPAU] to automate the location and authentication of servers.

The consumer of this protocol can be either a top-level application or another client/server protocol.

The following is a white-box diagram of protocols in the BITS peer-caching framework.

Figure 2: White-box diagram of protocols in BITS peer-caching framework

The following gives more detail on the role of protocols participating in the BITS framework:

The Background Intelligent Transfer Service (BITS) Upload Protocol [MC-BUP] is used to transfer large payloads from a client to a server or from a server to a client over networks with frequent disconnections, and to send notifications from the server to a server application about the availability of uploaded payloads. This protocol is layered on top of HTTP 1.1, uses several standard HTTP headers, and defines some new headers. The primary role of this protocol in the BITS Framework is for large payload transfer.

The Background Intelligent Transfer Service (BITS) Peer-Caching: Content Retrieval Protocol [MS-BPCR] is one protocol in a family of protocols that implement a distributed URL cache that is known as BITS peer-caching. A client uses the BITS) Peer-Caching: Content Retrieval Protocol to search an existing set of peers for content and to download from those peers. The primary role of this protocol in the BITS Framework is content retrieval.

The Background Intelligent Transfer Service (BITS) Peer-Caching: Peer Discovery Protocol [MS-BPDP] is used to locate hosts in a domain that supports the URL-caching protocol implemented by BITS. The protocol is implemented by using Web Services Dynamic Discovery (WS-Discovery), as specified in [WS-Discovery]. The primary role of this protocol in the BITS Framework is host discovery.

The p Background Intelligent Transfer Service (BITS) Peer-Caching: Peer Authentication Protocol [MS-BPAU] provides authentication for computers in a domain. The primary role of this protocol is peer authentication.

Figure 3: Protocol relationship for BITS