Ok.  So, here are the basics.  1st - the Publisher should typically NOT have phones registered to it.  The Subscriber is the primary call processing node.  So, your example would be this:

Phone goes off --> SCCP Off-Hook message goes to Subscriber

Subscriber says "Ok, you're off-hook you should hear dial tone" --> SCCP message goes to phone telling it to play dial tone

Phone dials 7035551212 --> For each digit, a SCCP message is sent to the Subscriber and it collects this digits for call processing, it finds a match

Subscriber sends a SCCP message to the phone with 7035551212 and tells the phone to ring

Subscriber sends a SCCP message to the dialing phone telling to to play ringback tone

Each party picks up and SCCP messages are received by the Subscriber and at this time, it sends each phone a Start Media Transmission message

At this point each phone opens up a channel to send/receive RTP streams directly to each other

The subscriber is not involved in the call flow unless one of the phones invokes a supplementary service (hold, transfer, etc) and then when each phone hangs up, the Subscriber sends a message to each phone to tear down the RTP channel between each phone.

Basic, but that's it.

Hailey

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