MikroTik – SIP / VoIP Configuration Guide

Table of Contents

Overview Before you start Ports used by VoIP Configuration 1. Disable SIP helper (SIP ALG) 2. Review FastTrack settings 3. Firewall rules 4. NAT configuration 5. QoS / Queueing Good practice Troubleshooting One-way audio Calls not establishing Strange/intermittent issues Poor call quality

Overview

This guide covers how to configure MikroTik routers for SIP-based VoIP.

MikroTik is very flexible, but that flexibility comes with a catch — the defaults aren’t always VoIP-friendly. Things like SIP helper, FastTrack, and connection tracking can all interfere if left as-is.

Once set up properly though, MikroTik is very stable.

Before you start

You’ll need:

WinBox / WebFig or CLI access
Understanding of your current firewall rules
SIP provider details

Ports used by VoIP

SIP: 5060 (UDP/TCP), sometimes 5061
RTP: typically UDP 10000–20000

Configuration

1. Disable SIP helper (SIP ALG)

From CLI:

/ip firewall service-port disable sip

Why this matters:
MikroTik’s SIP helper rewrites SIP traffic, which breaks NAT in many hosted VoIP setups. This is one of the first things to switch off.

2. Review FastTrack settings

FastTrack can bypass connection tracking, which SIP relies on.

Check your firewall rules:

/ip firewall filter print

If FastTrack is enabled:

Either disable it
Or exclude VoIP traffic from FastTrack

3. Firewall rules

Ensure SIP and RTP are not being blocked.

Example (simple case):

/ip firewall filter add chain=forward protocol=udp dst-port=5060 action=accept
/ip firewall filter add chain=forward protocol=udp dst-port=10000-20000 action=accept

In most setups, outbound is already allowed — just confirm nothing restrictive is in place.

4. NAT configuration

Standard masquerade is fine:

/ip firewall nat add chain=srcnat out-interface=WAN action=masquerade

For VoIP:

Avoid aggressive NAT rewriting
Keep mappings consistent

5. QoS / Queueing

If the link handles other traffic, prioritise RTP.

Simple queue example:

/queue simple add name="VoIP" target=LAN priority=1

Or use queue trees for more advanced setups.

Good practice

Keep configs simple — over-complication causes issues
Use address lists for provider IPs if locking down rules
Test after every major change

Troubleshooting

One-way audio

Check:

SIP helper is disabled
RTP ports allowed
FastTrack isn’t interfering

Calls not establishing

Look at:

Firewall rules
NAT
DNS resolution

Strange/intermittent issues

Often FastTrack or connection tracking related.

Try:

Disabling FastTrack temporarily

Poor call quality