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VoIP call issues over site-to-site VPN or with IPS configured

Resolve issues with VoIP call quality if you've configured a site-to-site VPN or IPS on Sophos Firewall.

Cause

If you've configured site-to-site VPN, IPS, or both on your Sophos Firewall, do as follows to resolve issues, such as VoIP call drops or poor quality calls:

Remedy

  1. Type: set ips sip_preproc disable

    This command turns off the preloaded IPS patterns for SIP.

  2. Type: set vpn conn-remove-tunnel-up disable

    When IPS patterns are turned off, Sophos Firewall does not flush the connections when IPsec tunnels come up.