What is sip alg?

SIP (Session Initiation Protocol) ALG (Application Layer Gateway) is a type of network protocol that manages and optimizes VoIP (Voice over Internet Protocol) communication by opening and closing ports in firewalls and ensuring that VoIP packets are correctly routed across different networks. SIP ALG enables the translation of IP addresses for SIP packets so that they can be used over public networks. It is a critical feature of routers and firewalls that support VoIP communication, allowing them to identify and interpret packets that contain signaling and voice data. SIP ALG is also sometimes referred to as SIP helper or SIP proxy and is used by most VoIP service providers to provide reliable and quality VoIP communication between devices on different networks. However, in some cases, SIP ALG can cause issues such as dropped calls, poor call quality, and latency issues. Therefore, it is essential to configure SIP ALG correctly to avoid any potential problems.