VoIP: Poor quality or calls getting dropped

12/20/2019 1855 21914

DESCRIPTION:

This KB applies when the VoIP traffic is in the same zone of the Data Traffic and the Security Services are enabled on that zone.

CAUSE:

The Security Services (Content Filtering, GAV, IPS, etc.) are affecting VoIP traffic due to useless inspection of the packets and sometimes the CF is blocking VoIP packets.

RESOLUTION:

Resolution/Workaround:

If you want to use the Security Services on the Data zone (i.e. LAN zone) but you want that the VoIP traffic is not being affected by those services, you should create a different "custom" zone for it and disable all the security services on the new zone.

Services which may affect VoIP traffic:

• Gateway AV --> only overloading
• IPS  --> only overloading
• Content Filter: it may also block VoIP traffic.
• App Control Advanced

For this reason, you may need to separate VoIP traffic from Data Traffic using two different zones. In this way you may apply different bandwidth policies, disable Security Services and useless inspections on VoIP traffic.

You can create a new zone in this way:

• Click Manage in the top navigation menu.
• Navigate to System Setup | Network | Zone and add a zone called VoIP . 
• Click Add.
• Then disable all the Security services as per screenshot below:
  
  
  
• Associate the required interfaces to the VoIP Zone by choosing the Zone as "VoIP" from the interfaces
• To Disable the CFS policy for the zone, follow these steps
  • Create a custom policy that is most permissive from Policies | Objects | Content Filter Objects | CFS Profile Objects and click ADD .
    
     
    
    
  • Navigate to Security Configuration | Security Services | Content Filter , under the CFS Policies click Add .
    
    
    
    

    NOTE: Be certain that you didn't apply any bandwidth policy on VoIP traffic or on the interface where the VoIP packets are going through.

     

• If this doesn't solve the issue, please check with your ISP or on your router (if any) if there are QoS services filtering your traffic.
• If possible, try to run VoIP traffic excluding the firewall and see if the issue persists.

If you followed all the steps in this article and you didn't solve the issue, please contact our support to deeply investigate on the issue.

There are two ways to contact technical support:

1. Online: Visit mysonicwall.com. Once logged in select Resources & Support | Support | Create Case. 

2. By phone: please use our toll-free number at 1-888-793-2830. Please have your SonicWall serial number available to create a new support case.

If you do not have a mysonicwall.com account create one for free!

Resolution for SonicOS 6.2 and Below

The below resolution is for customers using SonicOS 6.2 and earlier firmware. For firewalls that are generation 6 and newer we suggest to upgrade to the latest general release of SonicOS 6.5 firmware.

Resolution/Workaround:

If you want to use the Security Services on the Data zone (i.e. LAN zone) but you want that the VoIP traffic is not being affected by those services, you should create a different "custom" zone for it and disable all the security services on the new zone.

Services which may affect VoIP traffic:

• Gateway AV --> only overloading
• IPS  --> only overloading
• Content Filter: it may also block VoIP traffic.
• App Control Advanced

For this reason, you may need to separate VoIP traffic from Data Traffic using two different zones. In this way you may apply different bandwidth policies, disable Security Services and useless inspections on VoIP traffic.

You can create a new zone in this way

• Navigate to Network|Zones.
• Click Add.
• Then disable all the checkbox as per screenshot below.
  
  TIP: Please, follow this KB to see how to create zones: How To Create A Custom Zone.
  
  

  NOTE: Be certain that you didn't apply any bandwidth policy on VoIP traffic or on the interface where the VoIP packets are going through.
  
  

• If this doesn't solve the issue, please check with your ISP or on your router (if any) if there are QoS services filtering your traffic.
• If possible, try to run VoIP traffic excluding the firewall and see if the issue persists.

If you followed all the steps in this article and you didn't solve the issue, please contact our support to deeply investigate on the issue.

There are two ways to contact technical support:

1. Online: Visit mysonicwall.com. Once logged in select Resources & Support | Support | Create Case. 

2. By phone: please use our toll-free number at 1-888-793-2830. Please have your SonicWall serial number available to create a new support case.

If you do not have a mysonicwall.com account create one for free!