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Once channels are established and communicating between devices and Asterisk; where that data flows to depends on the channel type itself, its overall configuration, device specific configuration, signaling sent by the originating mechanism (a device, a command, an API call) and associated bridges. One or more channels could be talking to one or more channels over various bridges. What specifically Asterisk talks to on each channel is limited only by the technology implemented by the channel driver.
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The inbound channel is created from Alice's phone calling Asterisk. Asterisk then calls the extension dialed by Alice by creating an outbound channel to talk to Bob. Once the call is established the two channels are put into a bridgeBridges.
Fig 2
A user runs the originate command from AMI, or maybe something like "channel originate SIP/Alice application playback demo-congrats" from the CLI. Asterisk creates an outbound channel to call the device specified (SIP/Alice). When answered, Asterisk begins treating the channel like an inbound channel and connects it to the specified dialplan application.
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