Technical Tip: Enabling Quality of Service (QoS) for VoIP Traffic

[Hasnatriad]

Description	This article describes configuring Quality of Service (QoS) for VoIP traffic. This knowledge-based article provides step-by-step instructions on enabling QoS for VoIP services utilizing SIP port 5060 on a FortiGate firewall.
Scope	FortiGate.
Solution	Quality of Service (QoS) is an essential networking feature that prioritizes and efficiently manages network resources for specific applications and services. VoIP (Voice over Internet Protocol) services, such as communication using SIP (Session Initiation Protocol), depend on low latency and consistent network performance. FortiGate firewalls offer robust QoS capabilities to optimize network traffic and deliver a seamless VoIP experience. Configure the QoS profile for VoIP traffic: config firewall shaper traffic-shaper     edit "VoIP QoS"         set guaranteed-bandwidth 200         set maximum-bandwidth 200         set bandwidth-unit mbps         set diffserv enable         set diffservcode 101110     next end The details of Telephony Differentiated Services Code Point (DSCP) are explained in RFC3246. More about DSCP in Wikipedia. Also refer to this Technical Tip: Differentiated Services Code Point (DSCP) marking. Create a policy for SIP traffic and enable QoS policy. Applying QoS policy in the firewall policy can be done only on CLI. config firewall policy     edit 1         set name "VOIP_QoS"         set srcintf "port1"         set dstintf "port2"         set action accept         set srcaddr "all"         set dstaddr "all"         set schedule "always"         set service "SIP"         set logtraffic all         set nat enable         set traffic-shaper "VoIP QoS"         set traffic-shaper-reverse "VoIP QoS"     next end Once it is configured it can be modified in the GUI.   Related document: Admin Guide: Configuring traffic class IDs