OSF DCE Application Development Guide--Core Components

RPC Fundamentals
12.3.1 Server Binding Information
Binding information for a server is known as server binding information. A binding
handle that refers to server binding information is known as a server binding handle.
The use of server binding handles differs on servers and clients.
12.3.1.1 Server Binding On a Server
Servers use a list of server binding handles. Each represents one way to establish a
binding with the server. Before exporting binding information to a namespace, a server
tells the RPC runtime which RPC protocol sequences to use for the RPC interfaces the
server supports. For each protocol sequence, the server runtime creates one or more
server binding handles. Each server binding handle refers to binding information for a
single potential binding, including a protocol sequence, a network (host) address, an
endpoint (server address), a transfer syntax, and an RPC protocol version number.
12.3.1.2 Server Binding On a Client
A client uses a single server binding handle that refers to the server binding information
the client needs for making one or more remote procedure calls to a given server. Server
binding information on a client contains binding information for one potential binding.
On a client, server binding information always includes a protocol sequence and the
network address of the server’s host system. However, sometimes a client obtains
binding information that lacks an endpoint, resulting in a partially bound binding handle.
A partially bound binding handle corresponds to a system, but not to a particular server
instance. When a client makes a remote procedure call using a partially bound binding
handle, the client runtime gets an endpoint either from the interface specification (if one
a well-known endpoint is specified) or from the endpoint map on the server’s system.
Bindings almost never use well-known endpoints. Adding the endpoint to the server
binding information results in a fully bound binding handle, which contains an endpoint
and corresponds to a specific server instance. Note clients can get a partially bound
handle even if a server is not running.
12.3.2 Defining a Compatible Server
Compatible binding information identifies a server whose communications capabilities
(RPC protocol and protocol version, network and transport protocols, and transfer
syntax) are compatible with those of the client. Compatible binding information is
sufficient for establishing a binding. However, binding information is insufficient for
ensuring that the binding is to a compatible server.
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