1.1 Glossary
This document uses the following terms:
Augmented Backus-Naur Form (ABNF): A modified version of Backus-Naur Form (BNF), commonly used by Internet specifications. ABNF notation balances compactness and simplicity with reasonable representational power. ABNF differs from standard BNF in its definitions and uses of naming rules, repetition, alternatives, order-independence, and value ranges. For more information, see [RFC5234].
base64 encoding: A binary-to-text encoding scheme whereby an arbitrary sequence of bytes is converted to a sequence of printable ASCII characters, as described in [RFC4648].
binary large object (BLOB): A discrete packet of data that is stored in a database and is treated as a sequence of uninterpreted bytes.
certificate: A certificate is a collection of attributes and extensions that can be stored persistently. The set of attributes in a certificate can vary depending on the intended usage of the certificate. A certificate securely binds a public key to the entity that holds the corresponding private key. A certificate is commonly used for authentication and secure exchange of information on open networks, such as the Internet, extranets, and intranets. Certificates are digitally signed by the issuing certification authority (CA) and can be issued for a user, a computer, or a service. The most widely accepted format for certificates is defined by the ITU-T X.509 version 3 international standards. For more information about attributes and extensions, see [RFC3280] and [X509] sections 7 and 8.
channel lifetime: The maximum content length of an IN channel or OUT channel (in bytes).
channel recycling: The set of mechanisms involved in closing an open IN or OUT channel N and opening a new IN or OUT channel N+1. The opening and subsequent closing occur as part of the sequence of channels forming a virtual IN or OUT channel.
client: A computer on which the remote procedure call (RPC) client is executing.
dynamic endpoint: A network-specific server address that is requested and assigned at run time. For more information, see [C706].
echo request: A message sent to an inbound proxy or outbound proxy in order to elicit a response.
echo response: A message sent by an inbound proxy or outbound proxy in response to an echo request.
endpoint: A network-specific address of a remote procedure call (RPC) server process for remote procedure calls. The actual name and type of the endpoint depends on the RPC protocol sequence that is being used. For example, for RPC over TCP (RPC Protocol Sequence ncacn_ip_tcp), an endpoint might be TCP port 1025. For RPC over Server Message Block (RPC Protocol Sequence ncacn_np), an endpoint might be the name of a named pipe. For more information, see [C706].
expire: A process in which an object, such as an external data connection, becomes invalid because its allotted time period has ended.
HTTP client: A program that establishes connections for the purpose of sending requests, as specified in [RFC2616].
HTTP proxy: An intermediary program that acts as both a server and a client for the purpose of making requests on behalf of other clients. For more information, see [RFC2616].
HTTP server: An application that accepts connections in order to service requests by sending back responses. For more information, see [RFC2616].
IN channel: An inbound HTTP request or an inbound TCP/IP connection between two network nodes acting in one of the roles defined by this protocol. An IN channel is independent from the underlying transport and can be based on an HTTP or HTTPS request or on a TCP connection.
IN channel recycling: The set of mechanisms involved in closing an open IN channel N and opening a new IN channel N+1. The opening and subsequent closing occur as part of the sequence of channels forming a virtual IN channel.
inbound: The network traffic flowing from the client to the server.
inbound proxy: A network node that acts as an RPC over HTTP proxy for inbound traffic between an RPC client and an RPC server.
Internet host name: The name of a host as defined in [RFC1123] section 2.1, with the extensions described in [MS-HNDS].
little-endian: Multiple-byte values that are byte-ordered with the least significant byte stored in the memory location with the lowest address.
mixed proxy: A network node that acts as a proxy for both inbound and outbound traffic between a client and a server.
OUT channel: An outbound HTTP response or an outbound TCP/IP connection between two network nodes acting in one of the roles defined by a protocol. An OUT channel is independent from the underlying transport and can be based on an HTTP or HTTPS response or on a TCP connection.
OUT channel recycling: The set of mechanisms involved in closing an open OUT channel N and opening a new OUT channel N+1. The opening and subsequent closing occur as part of the sequence of channels forming a virtual OUT channel.
outbound: Network traffic flowing from the server to the client.
outbound proxy: A network node that acts as an RPC over HTTP proxy for outbound traffic between an RPC client and an RPC server.
PDU stream: An ordered sequence of RPC and RPC over HTTP protocol data units.
plugged channel mode: A channel mode in which an IN channel or OUT channel instance queues protocol data units (PDUs) instead of sending them immediately.
predecessor channel: In the context of IN channel recycling or OUT channel recycling, the previous IN channel or OUT channel (–1 where N is the reference point) in the sequence of channels forming a virtual IN channel or virtual OUT channel.
predecessor inbound proxy: An inbound proxy to which a predecessor channel was established.
predecessor outbound proxy: An outbound proxy to which a predecessor channel was established.
protocol data unit (PDU): Information that is delivered as a unit among peer entities of a network and that can contain control information, address information, or data. For more information on remote procedure call (RPC)-specific PDUs, see [C706] section 12.
protocol dialect: A protocol version that is distinct and non-interoperable from other protocol versions from the same group of related protocols.
proxy: A network node that accepts network traffic originating from one network agent and transmits it to another network agent.
receive window: The amount of memory that a recipient of network traffic has committed to queuing protocol data units (PDUs) that it cannot process immediately.
remote procedure call (RPC): A communication protocol used primarily between client and server. The term has three definitions that are often used interchangeably: a runtime environment providing for communication facilities between computers (the RPC runtime); a set of request-and-response message exchanges between computers (the RPC exchange); and the single message from an RPC exchange (the RPC message). For more information, see [C706].
replacement channel: An IN channel or OUT channel other than the first in the sequence of IN channels or OUT channels that constitute a virtual IN channel or virtual OUT channel.
Request to Send (RTS) cookie: A 16-byte cryptographically strong random number exchanged between parties in a remote procedure call (RPC) over HTTP protocol sequence. An RTS cookie has the same uniqueness requirements as a UUID, and implementations can use a UUID as the RTS cookie. An RTS cookie is used to reference virtual connections, IN channels, OUT channels, and other protocol entities.
Request to Send (RTS) Protocol Data Unit (PDU): A PDU that is used to control communication settings on an IN channel or OUT channel, virtual IN channel or virtual OUT channel, or virtual connection.
RPC client: A computer on the network that sends messages using remote procedure call (RPC) as its transport, waits for responses, and is the initiator in an RPC exchange.
RPC over HTTP proxy: A mixed proxy, inbound proxy, or outbound proxy.
RPC PDU: A protocol data unit (PDU) originating in the remote procedure call (RPC) runtime. For more information on RPC PDUs, see [C706] section 12 and [MS-RPCE] section 2.
RPC protocol sequence: A character string that represents a valid combination of a remote procedure call (RPC) protocol, a network layer protocol, and a transport layer protocol, as described in [C706] and [MS-RPCE].
RPC server: A computer on the network that waits for messages, processes them when they arrive, and sends responses using RPC as its transport acts as the responder during a remote procedure call (RPC) exchange.
RPC transport: The underlying network services used by the remote procedure call (RPC) runtime for communications between network nodes. For more information, see [C706] section 2.
server: A computer on which the remote procedure call (RPC) server is executing.
successor channel: In the context of IN channel recycling or OUT channel recycling, the next IN channel or OUT channel in the sequence of channels forming a virtual IN channel or virtual OUT channel (N+1 where N represents the reference point in the sequence).
successor inbound proxy: An inbound proxy to which a successor channel is established.
successor outbound proxy: An outbound proxy to which a successor channel is established.
Uniform Resource Identifier (URI): A string that identifies a resource. The URI is an addressing mechanism defined in Internet Engineering Task Force (IETF) Uniform Resource Identifier (URI): Generic Syntax [RFC3986].
universally unique identifier (UUID): A 128-bit value. UUIDs can be used for multiple purposes, from tagging objects with an extremely short lifetime, to reliably identifying very persistent objects in cross-process communication such as client and server interfaces, manager entry-point vectors, and RPC objects. UUIDs are highly likely to be unique. UUIDs are also known as globally unique identifiers (GUIDs) and these terms are used interchangeably in the Microsoft protocol technical documents (TDs). Interchanging the usage of these terms does not imply or require a specific algorithm or mechanism to generate the UUID. Specifically, the use of this term does not imply or require that the algorithms described in [RFC4122] or [C706] must be used for generating the UUID.
unplug a channel: To switch a channel from plugged channel mode to unplugged channel mode.
unplugged channel mode: A channel mode in which an IN channel or OUT channel instance sends protocol data units (PDUs) immediately instead of queuing them. This is the default mode for channels.
virtual connection: A pair consisting of one virtual IN channel and one virtual OUT channel between the same remote procedure call (RPC) client and RPC server that provides full-duplex, reliable, in-order, at-most-once delivery communication capabilities.
virtual IN channel: A communication session between a remote procedure call (RPC) client and an RPC server that can span multiple IN channels. When the communication session spans multiple IN channels, the IN channels are sequentially ordered in time with partial overlap in time between channel N and channel N+1 in the sequence. A virtual IN channel provides half-duplex, RPC client-to-RPC server, reliable, in-order, at-most-once delivery communication capabilities.
virtual OUT channel: A communication session between a remote procedure call (RPC) client and an RPC server that can span multiple OUT channels. When the communication session spans multiple OUT channels, the OUT channels are sequentially ordered in time with partial overlap in time between channel N and channel N+1 in the sequence. A virtual OUT channel provides half-duplex, RPC server-to-RPC client, reliable, in-order, at-most-once delivery communication capabilities.
well-known endpoint: A preassigned, network-specific, stable address for a particular client/server instance. For more information, see [C706].
MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.