You should disable SIP ALG because it: Interrupts SIP traffic like calls and conferencing apps. Affects the perceived reliability of desk phones and VoIP apps. Isn't needed when using cloud-based VoIP providers.

Is ALG necessary?

The data stream parameters, which include network parameters such as IP addresses and port numbers, are sent in the control packets. ALG services are necessary so that devices can open ports dynamically in their firewalls to permit data packets through and assign the correct Aerohive QoS class to the data traffic.

Should I disable SIP ALG for gaming?

SIP ALG modifies SIP packets in unexpected ways, corrupting them and making them unreadable. ... Therefore if you are experiencing problems we recommend that you check your router settings and turn SIP ALG off if it is enabled.