I am trying to learn the basics about security so I started by scanning the IP of a friend using Nmap, I have some questions about this section:

PORT STATE SERVICE VERSION

3389/tcp open tcpwrapped

| ssl-cert: Subject: commonName=Ventas-gp-1

| Issuer: commonName=Ventas-gp-1

| Public Key type: rsa

| Public Key bits: 2048

| Signature Algorithm: sha1WithRSAEncryption

| Not valid before: 2016-09-25T12:11:37

| Not valid after: 2017-03-27T12:11:37

| MD5: 95cf e484 a18f 98d1 49f1 186b 45ad ee62

|_SHA-1: 53c8 b5f3 4424 0863 7d2e 42e3 f09c 3148 1c1d dafa

|_ssl-date: 2017-02-17T12:41:06+00:00; +2m26s from scanner

This is obviously about a Remote Desktop, but with all the information about encryption, could this be used to crack the windows password? passing this data to "John the ripper" for example

Also in this network there is a Voip phone, this phone is in the DMZ of the router and also in the router the TCP 5060 is open, but none of this are shown in my Nmap output, I want to know why? I am using: -T4 -A -v

Thanks