Internet connections that are heavily utilized will experience call quality degradation and an overall poor experience with hosted voice. Like most hosted VoIP solutions, SpectrumVoIP’s services work best with consistently low ping times and 60-90 kbps per concurrent phone call.

This document provides guidance for configuring a SonicWALL for SpectrumVoIP services. Included are instructions for traffic prioritization. This uses features within the SonicWALL firewall to appropriately prioritize VoIP-related traffic above all other Internet traffic to help ensure a positive experience.

Recommended Adjustments

Before learning how you can optimize your Sonicwall's settings for use with VoIP reliant devices, it is recommended to read the sections below to review the different adjustments suggested by our team, such as ports and subnets to allow traffic to use, bandwidth requirements, and more.

Subnet and Port Configuration

Read the sections below to allow traffic from the services in use by your company. If you not using a specific service, such as Stratus users that do not use our Enswitch platform and vice versa, you can avoid opening the ports used by that service.

SpectrumVoIP Public Subnets

• 199.71.209.0/24
• 24.227.249.0/25
• 72.249.136.32/28
• 206.123.122.32/27
• 212.69.157.32/27
• 40.143.31.64/27
• 45.41.5.0/24
• 12.150.91.0/24

Ports - Stratus Platform

Main Utilized Ports

• 5060-5062 UDP - SIP
• 20,000-40,000 UDP - RTP
• 80, 443 TCP - HTTP/HTTPS

Portal Dynamic Updates

• 8001 - TCP

Text-to-Speech Services - TCP and UDP

• 35.175.185.150:3001
• 35.175.185.150:8000
• 44.212.88.215:8000
• 54.149.243.27:3001
• 54.149.243.27:8000
• 54.70.235.134:3001
• 54.70.235.134:8000

StratusFAX 2.0 - TCP

• 5066 TCP - HTTPS and HTTP

StratusMEETING - TCP and UDP

• 54.188.133.147:3443
• 3.130.158.184:3443
• 35.183.150.146:3443

StratusWEB PHONE

• 9002 - TCP - websockets

Ports - Enswitch 1 and 2 Platforms

• 5060-5062 UDP - SIP
• 10,000-20,000 UDP - RTP
• 80, 443 TCP - HTTP/HTTPS

Push Notifications Ports

Android and Google Devices - Google's Firebase Cloud Messaging, aka FCM

• 443, 5228, 5229, 5230 - TCP

Apple Devices - Apple Push Notification Service, aka APNs

• 5223, 443, 2197 - TCP

Bandwidth Requirements

Voice-only applications utilize G.711 U-Law as the primary codec and require 87.2 kbps of bandwidth per active call. 

It is recommended to round the requirement up to 100 kbps to account for signaling and overhead.

Assign a Voice VLAN to Phones

Creating a dedicated VLAN for your different groups of IP devices, such as your desk phones, is a great way to simplify managing your network and troubleshooting future issues with those devices. It is generally recommended to use VLANs to isolate IP devices to reduce the risk of unauthorized access to these devices and limit the spread of potential threats within your network. Segmenting a network using VLANs can also help reduce congestion and improve a network's overall performance, which can be a great boon for networks with many VoIP devices. 

Many models of gateways and network switches allow you to automatically place VOIP devices on a dedicated VLAN. There are several ways to accomplish this:

Manual/Static Port Configuration

This is the most basic method, requiring explicit, per-port configuration by a network administrator. It is typically used when automated discovery is not available or desired. The switch port must be configured as an access port with a specific voice VLAN setting. The switch is explicitly told to use a specific Data VLAN for untagged traffic (for the connected PC) and a specific Voice VLAN for tagged (802.1Q) traffic. Any traffic arriving on that port that is untagged is placed into the Data VLAN, and any traffic tagged with the Voice VLAN ID is placed into the Voice VLAN. The IP phone must be manually configured (or use a secondary method like DHCP) to tag its voice traffic correctly. 

Automatic Discovery via LLDP/CDP 

If your network switches support Link Layer Discovery Protocol (LLDP), LLDP Media Endpoint Discovery (LLDP-MED), and/or Cisco Discovery Protocol (CDP), Grandstream, Yealink, and Polycom desk phones are compatible with these protocols and can utilize them to be discovered by neighbor devices and switches. 

If your network switch does offer LLDP, LLDP-MED, or CDP, it is recommended to ensure these protocols are enabled and configured to point to your desired VLAN. Doing so will allow the switches to discover compatible IP phones and set the devices in a VLAN dynamically depending on the device's configuration information. 

Option 132 for Yealink Phones

Option 132 in DHCP is a feature that enables automatic VLAN assignment. When a device connects to the network, it sends a DHCP request containing its MAC address. The DHCP server that has Option 132 configured identifies the device and assigns a suitable VLAN. 

To create a DHCP VLAN option on your DHCP server to allow Yealink phones to automatically connect and provision when plugged in, the following can be configured:

• Option 132: Set Voice VLAN ID
• Type: String (ASCII)
• Value : 'VLANTAG' for example '20' for VLAN 20

This DHCP option should be applied to your native DHCP server so that the phones receive the configuration when first plugged in. This may also be applied to the voice VLAN if needed.

Configure Your Sonicwall's VoIP Settings

SonicOS includes VoIP configuration settings on the VoIP → Settings page. 

Although there are many settings that can be adjusted on a Sonicwall firewall, this guide will only explore settings that affect the performance of your VoIP services with SpectrumVoIP. 

Enable Consistent NAT

Enabling Consistent NAT causes a slight decrease in overall security, because of the increased predictability of the address and port pairs. Most UDP-based applications are compatible with traditional NAT; therefore, we recommend enabling Consistent NAT unless your network uses applications that require this disabled.

To enable Consistent NAT, select Enable consistent NAT and click the Accept button. This option is disabled by default.

Disable SIP Transformations

In the Sonicwall's SIP Settings, the Enable SIP Transformations setting is enabled by default. Having this setting enabled can commonly cause quality of service issues with VoIP calls. 

It is recommended to disable SIP Transformations to avoid one-way audio and issues with parking and transferring. 
To disable SIP Transformations, deselect the Enable SIP Transformations option.

Prioritize SpectrumVoIP Traffic

One of the greatest challenges for VoIP is ensuring high speech quality over an IP network. VoIP and other types of media streaming are very sensitive to delay and packet loss. Managing access and prioritizing traffic are important requirements for ensuring high-quality, real-time VoIP communications.

To prioritize SpectrumVoIP traffic, you must create four Address Objects and combine them into an Address Group, then create firewall rules to allow and prioritize traffic destined for this Address Group.

Step 1: Create Address Objects

1. Navigate to Network → Address Objects.
2. Click Add to create the following new address objects listed in the table below.
   

   Note: Ensure that the Zone Assignment is set as WAN and Type is set as Network for each.

    

Step 2: Add an Address Group

1. After creating the address objects above, click Add Group.
2. Name the group “SpectrumVoIP Subnets”.
3. Add the four, new SpectrumVoIP Address Objects to the group using the right arrow. 

Step 3: Create Firewall Access Rules

1. Navigate to Firewall → Access Rules. 
2. In the LAN to WAN rules section, click Add.
3. In the General tab, configure the following:
   • Service - Set to Any.
   • Source - Set to Any.
   • Destination - Select the SpectrumVoIP Subnets address group.
4. On the Traffic Shaping tab, do the following:
   • Egress Bandwidth Management - Enable this function.
   • Ingress Bandwidth Management - Enable this function.
   • Bandwidth Priority - Select 0 Realtime for both.
     

     Note: Bandwidth Management will need to be enabled globally to allow the per-firewall rule BWM tab to be accessible.

      

Step 4: Add a Service Object

1. Navigate to Network → Services and click Add.
2. Add a new Service Object with the following configured:
   • Name - Type SpectrumVoIP RTP.
   • Protocol - Select UDP (17).
   • Port Range - Select 20,000-40,000.

Step 5: Create a Service Group

1. Select Service Groups → Add Group.
2. Give the new service group a Name, such as “SpectrumVoIP Voice”.
3. Move the SIP and SpectrumVoIP RTP options the right section using the arrows. 
4. Click Add.

Use Option 66: Phone Provisioning via DHCP

If your Sonicwall will act as a DHCP server, you can set it to utilize Option 66 to make it simpler to install and provision your desk phones. 

When Option 66 is configured, phones that boot up and connect to the Sonicwall will be provided a Provisioning URL. When the phones use the Provisioning URL to connect to our TFTP server, they can request and apply a config file to make setting up and updating themselves more streamlined.

To configure Option 66 for your Sonicwall, this can be done by creating an Option Object in its DHCP Advanced Settings.

1. Login to the SonicWall Management GUI
2. Navigate to Network → System → DHCP Server.
3. Click the Advanced button next to the Enable DHCPv4 Server option.
4. On the Option Objects tab of the DHCP Advanced Settings window, click the + Add button.
5. Enter the following information:
   • Option Name: Enter a name for this object, such as “Option 66”.
   • Option Number: Select 66 (TFTP Server Name)
   • Option Value: Enter the URL for our provisioning server provided by a SpectrumVoIP Installer or Technician. 
     

     Note: If you do not have this URL, contact your SpectrumVoIP Installer or our Technical Support team for further assistance.

      
6. Click the Save button.
   

   ✔ Once you have created an Option 66 Option Object, you can assign it to existing DHCP Server Lease Scopes that are assigned to subnets your desk phones will be connected to. 

    

Quality of Service

QoS encompasses a number of methods intended to provide predictable network behavior and performance. Network predictability is vital to VoIP services. QoS, when configured and implemented correctly, can properly manage traffic and guarantee the desired levels of network service.

Manage Bandwidth on a WAN Interface

Bandwidth Management (BWM) can be configured by enabling BWM on a relevant WAN interface and specifying the available bandwidth on the interface in Kbps. This is performed from the Network → Interfaces page by selecting the Configure icon for the WAN interface, and navigating to the Advanced tab.

Egress and Ingress BWM can be enabled jointly or separately on WAN interfaces. Different bandwidth values may be entered for outbound and inbound bandwidth to support asymmetric links. Link rates up to 100,000 Kbps (100Mbit) may be declared on the Fast Ethernet interface, while Gigabit Ethernet interfaces will support link rates up to 1,000,000 (Gigabit). ad

Once one or both BWM settings are enabled on the WAN interface and the available bandwidth has been declared, a Bandwidth tab will appear on Access Rules.

To configure Bandwidth Management on your SonicWALL…

1. Navigate to Network → Interfaces.
2. Click the Edit icon in the Configure column in the WAN (X1) line of the Interfaces table.
3. In the Edit Interface window, the Advanced tab.
4. Select Enable Egress (Outbound) Bandwidth Management and enter the available bandwidth in the Available Interface Egress Bandwidth Management field.
5. Select Enable Ingress (Inbound) Bandwidth Management and enter the available bandwidth in the Available Interface Ingress Bandwidth Management field.
6. Click OK.

Enable VoIP Logging

You can enable the logging of VoIP events on the Log → Settings page. Log entries are displayed on the Log → Monitor page. To enable logging of VoIP, see Log → Settings.