Why we do not recommend using VPNs and SASE with the Softphone

We do not recommend using VPNs and SASE with the softphone for various reasons. 

VPNs and SASE can impact VoIP calls in several ways:

• Latency and Call Quality: VPNs can introduce additional latency because your data has to travel through the VPN server before reaching its destination. Higher latency can lead to delays, echoes, or dropped calls. With SASE, network congestion or misconfiguration can still lead to latency issues.
• Bandwidth Limitations: Some VPNs might have bandwidth restrictions that can reduce the quality of your VoIP calls. If the VPN is congested, it can affect call clarity and stability. If a SASE provider has bandwidth limitations, competing data-heavy applications could impact call clarity and stability.
• Encryption Overhead: While VPNs encrypt your data for security, this encryption can add overhead, potentially affecting call quality if the VPN connection isn’t optimized. With SASE, excessive security policies or deep packet inspection can add overhead, slightly affecting call quality. If encryption settings are too aggressive, real-time VoIP communication might experience minor delays.
• Geolocation Issues: Using a VPN can change your apparent location, which may affect the routing of your calls. Some VoIP services may not work correctly or impose additional charges based on the perceived location. With SASE, if traffic is forced through certain points of presence, it may alter perceived location similar to VPNs. This can affect call routing efficiency or VoIP service functionality in certain regions.
• Firewall and Port Issues: Some VPNs might block specific ports that VoIP services use, leading to issues with call connectivity. Ensuring your VPN allows the necessary ports for your VoIP service is essential. If SASE is configured too restrictively, it might block or throttle VoIP traffic. Misconfigured access policies could prevent certain VoIP services from functioning smoothly.
• Reliability: Depending on the VPN or SASE service, connections can be less stable than a direct connection. Unstable connections can result in call drops or interruptions.

Please see this article for IP Addresses for Whitelisting.