Need clarification on ports used in SIP (Cisco Phone)

Ok, I’m little confused with what ports is what

I’m trying to understand whats needed. In my Asterisk host I opened firewalld for 5060 (SIP protocol) and range 15000-15100 for RTP. From what I understand, each active channels will use 2 ports from RTP pool. I don’t expect more than 50, so I narrowed it down to this range. Same ports forwarded through the company router to outside world.

Now, I was setting up Cisco phone following those instructions and got little confused on what I’m doing and why. Phone installed at home, behind another router. (everything works, I just want to understand)

First confusion:
Phone have it specified that SIP port 5060.
Why do I need so specify on proxy: ?
Also, there is a recommendation to start with number and go up for each consecutive port. Next phone will be 5061 and so on. How are those all ports relate to each other?

Also, I had RingCentral phone before and they wanted ports “triggered”, not “forwarded”. Is there some simple instructions or article on how this works and what all of those terms mean?

Using 5061 etc., is a tactic for dealing with NAT. It is not specific to SIP.

The proxy things sounds like a Cisco thing. Simple Asterisk configurations don’t have explicit proxies.

Cisco SPA or 7900 series?

You probably don’t. Phone should default to 5060.

Asterisk SPA504G … eepbx-2714

It just stopped working again. I was cleaning up sip.conf, changed all passwords to complex ones. Now (of course I changed password in Cisco setup) - it won’t register… Didn’t spend much time yet to figure it out…

Is there any restrictions on what passwords can be used? I used pwd generator and they all 8 charchters with upper/lower case letters and numbers