VOIP Fritzbox behind Sohos XG

Question

Hello, 
 last time I got many problems with VOIP. Sometime it works great and another day it won't work. 
 
 Does someone get some experiances between SIP an VOIP with an Fritzbox 7490 ? 
 
 My Firewall rule is shown below.

The content of SIP Fritz is:

Or should I try it with an Portforwarding Rule ? 
 But i there a difference between a portforwarding and a "Network Rule" ? 
 
 Thanks 4 your help

lferrara · Answer

Mario, 
 On dnat when the rewrite source address is enabled, the origin ip will be masqueraded to XG Ip and your destination LAN up will se the request coming from XG. 
 The ports you opened are ports needed by the fritz box, I guess.