D-Link models (DIR-615-628-825+) Configuration Guide

Introduction

This guide provides our recommended configuration for D-Link routers (DIR series, DGL series) to ensure optimal VoIP performance.

If you notice any of the following, this guide is for you:

Symptom	Description
Phone deregistration	Phones showing "Not Registered" when they shouldn't
One-way audio	You can hear the other party, but they can't hear you (or vice versa)
Dropped calls	Calls disconnect after a specific time period
No incoming calls	Phone doesn't ring for incoming calls
Call transfer failures	Parties can't hear each other after transfers
Call hold issues	Audio doesn't return after placing a call on hold

Series	Popular Models	Notes
DIR Series	DIR-615, DIR-628, DIR-825, DIR-855, DIR-860, DIR-868, DIR-878, DIR-882	SIP ALG under Advanced > Firewall > SIP
DGL Series	DGL-4100, DGL-4500, DGL-5500	Gaming routers, same SIP ALG location
DSL Series	DSL-2750, DSL-2900AL, DSL-2877AL, DSL-2888A	Modem/routers, SIP ALG under Advanced > Firewall

Important: You need to configure the following settings on your D-Link router.

Critical: SIP ALG is enabled by default on most D-Link routers and MUST be disabled for proper VoIP operation.

Navigation	Setting	Action
`Advanced > Firewall > SIP`	Log in to your router	Open browser to `192.168.0.1` or `192.168.1.1`
	Go to Advanced	Click Advanced tab at the top
	Navigate to Firewall	Click Firewall in the left menu
	Find SIP ALG setting	Look for SIP, SIP ALG, or SIP Endpoint
	Disable SIP ALG	❌ UNCHECK the box and click Save

Navigation	Setting	Value
`Advanced > Port Forwarding`	Name	VoIP or SIP
	Protocol	UDP / Both
	Start Port	`5060`
	End Port	`5061` (SIP) and `10000-20000` (RTP)
	IP Address	Your VoIP device's IP (use static/reservation)

Navigation	Setting	Action
`Advanced > QoS`	Enable QoS	✅ CHECK Enable QoS
`Advanced > QoS`	Priority	Set High priority for VoIP device IP or ports

Ensure your VoIP device always receives the same IP address for port forwarding to work reliably.

Navigation	Setting	Action
`Setup > Network Settings > DHCP Reservation`	Enable DHCP Reservation	Select your VoIP device from list
`Setup > Network Settings > DHCP Reservation`	Save Settings	Click Save Settings

Pro tip: After making changes, reboot your router and VoIP device for settings to take effect.

Create a port forwarding rule to allow traffic from our servers to reach your VoIP device.

Note: The /27 notation includes 32 IP addresses ranging from 64.26.133.64 to 64.26.133.95.

#	Task
1	SIP ALG disabled in Advanced > Firewall
2	Port forwarding configured for SIP (5060-5061) and RTP (10000-20000)
3	QoS enabled with VoIP priority (optional)
4	Address reservation set for VoIP device
5	Whitelist rule created for `64.26.133.64/27`
6	Test call successful with two-way audio

Test URL: http://mcstest.visualware.com/myspeed/myvoiph5_g711_sipalg.html

Item	Detail
Requirement	Download the BCS utility when prompted
Expected Result	`SIP ALG Firewall: N`
If Result Shows "Y"	SIP-ALG is still active. Re-check Advanced > Firewall settings.

Test Case	Procedure	Expected Result
Outbound Call	Place call to external number	Two-way audio established
Inbound Call	Call in from external number	Phone rings, call connects with two-way audio
Call Hold/Resume	Place call on hold, then resume	Audio returns successfully
Call Transfer	Transfer an active call	Transfer completes, parties can communicate

Issue	Most Likely Cause	Solution
One-way audio	SIP ALG still enabled	Re-check Advanced > Firewall > SIP
No incoming calls	Port forwarding missing	Verify port forwarding for UDP 5060-5061 and 10000-20000
Registration fails	SIP ALG or IP conflict	Check SIP ALG status and use static IP for VoIP device
Phones re-registering constantly	SIP ALG still interfering	Run SIP-ALG test and verify settings

For visual guidance on configuring your D-Link router, visit the official D-Link support page: