Firewall Configuration and SIP ALG
This topic covers issues related to your business phone system's traffic being blocked or altered due to firewall policies, SIP Application-Level Gateway (SIP ALG), port restrictions, security filtering, or access rules. If you're experiencing one-way audio calls, phones failing to register, blocked ports, or a change in your security device, this guide may help.
Note: This page does not address issues related to DNS-only problems.
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If you need further assistance, please provide us with your firewall model, public IP, affected ports/protocols, SIP ALG status, any available packet evidence, and details of recent policy changes. Our team will do our best to help you resolve the issue.
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