Signals Image Artist: What is the communication pathway for Harmony to SImA data transfer?

During Harmony -> SImA transfers the following happens:

1) Harmony establishes a connection to SImA.

2) Harmony pushes an XML file to SImA. The XML contains a list of URLs which point to the network location of the individual images as stored on the Harmony PC.

3) SImA uses the URLs to download (http get) the images directly from Harmony. 

4) Whilst the transfer is being processed, Harmony regularly polls SImA to query the status of the job.

The communication is bi-directional; during steps 1), 2) and 4) the communication is from Harmony -> SImA, and during step 3) the communication is from SImA -> Harmony

Firewall TCP Port exception requirements: 

Port 443 (HTTPS): Used for initial connection establishment when a user logs in to SImA via the Harmony UI.
Port 80 (HTTP): Used for data transfer from Harmony to SImA after the initial connection.