H3C Technologies H3C SR8800 - Manual (Page 103)

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Configuring IPC
IPC overview
Inter-Process Communication (IPC) is a reliable communication mechanism among different nodes. The
following are the basic concepts in IPC.
Node
An IPC node is an independent IPC-capable processing unit, typically, a CPU.
• Typically a router is available with multiple boards, each having one CPU, and some boards are
available with multiple CPUs. Some routers may be available with multiple CPUs, for example
service CPU and OAM CPU. Therefore, a router corresponds to multiple nodes.
• An Intelligent Resilient Framework (IRF) virtual device is an interconnection of several centralized
routers, with each member router corresponding to one or more nodes. Therefore, an IRF virtual
device corresponds to multiple nodes.
Therefore, in actual application, IPC provides a reliable transmission mechanism between different
routers and boards.
Link
An IPC link is a connection between any two IPC nodes. There is one and only one link between any two
nodes for sending and receiving packets. All IPC nodes are fully connected.
IPC links are created when the system is initialized. An IPC node, upon startup, sends handshake packets
to other nodes. If the handshake succeeds, a connection is established.
The system uses link status to identify the link connectivity between two nodes. An IPC node can have
multiple links, each having its own status.
Channel
A channel is a communication interface for an upper layer application module of a node to
communicate with an application module of a peer node. Each node assigns a locally unique channel
number to each upper layer application module for identification.
Data of an upper layer application module is sent to the IPC module through a channel, and the IPC
module sends the data to a peer node through the link. The relationship between a node, link and
channel is as shown in
Figure 34 .