Configuring Ipc; Overview; Node; Link - HP 5500 EI Series Configuration Manual

Configuring IPC

This chapter provides an overview of Inter-Process Communication (IPC) and describes the IPC
monitoring commands.

Overview

IPC provides a reliable communication mechanism among processing units, typically CPUs. IPC is
typically used on a distributed device or in an IRF fabric to provide reliable inter-card or inter-device
transmission. This section describes the basic IPC concepts.

Node

An IPC node is an independent IPC-capable processing unit, typically, a CPU.
The device is a centralized device that has only one CPU. The IRF fabrics formed by them have multiple
CPUs, or IPC nodes.

Link

An IPC link is a connection between any two IPC nodes. Any two IPC nodes have one and only one IPC
link for sending and receiving packets. All IPC nodes are fully meshed.
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, and each link has its own status.

Channel

A channel is the communication interface between peer upper layer application modules that use
different IPC nodes. Each node assigns a locally unique channel number to each upper layer application
module for identification.
An upper layer application module sends data to an IPC module in a channel, and the IPC module sends
the data to a peer node across a link, as shown in Figure 54.
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