RTP Stream in a call

hi guys,

as per the diagram https://imgur.com/a/MrN7I

I am making a call from Star Trinity (laptop VoIP tester) to an E1 to IP gateway, which is just routing the call to another gateway and out to an E1 phone...

When a call is taking place from Star Trinity to the E1 phone, when I log into the gateway in network 1, I can see 2 voip calls active (in then out) for the duration of the call....

However, in Star Trinity, it is monitoring the session between it to network 2's gateway...

My question is, is the RTP stream directly between the two devices, or is it via network 1's gateway (like in the diagram, the red hops).

If it is directly, then why have I got two VoIP calls active on network 1's gateway?

(edit: additional info.. The initial call from Star trinity is to gateway in network 1, but the routing in gateway 1 sends it to gateway 2 then to the E1 phone)