Mangle function for phones ?

RouterOS Beginner Basics
1

Hello,
From the wiki:

Mangle is a kind of ‘marker’ that marks packets for future processing with special marks

Does it mean that mangle is useless if we have one ip phone and one softphone on the lan ?

2

Not at all. You can mark in many different ways to identify traffic. VoIP is quite simple to “catch”. See my sig.

3

But without a PBX on the LAN, what is the interest to mark the VOIP traffic ?

4

What happens if a user is consuming all of the available bandwidth? VoIP calls will sound horrible at the least and most likely drop the call. Its important to properly QOS the network to ensure that everything works as desired. Perhaps you would want to throttle non VoIP traffic so at to prevent saturation.

5

What I want to do:

I have a SIP provider who has 8 servers. Then I created an addres-list called SIP_Provider
I have three phones (one ip phone and two softphones) on my lan 192.168.1.0. Then I created an address-list called Phones

I want to forward the voip traffic (sip+rtp) from SIP_Provider to Phones

I must use probably NAT in a first step
After my question was on the utility of mangle for my case