Calls dropping to mobile phones after upgrade to v20. On Prem

[nickster]

We recently went from v18 to v20. Since the upgrade, we are having a lot of dropped calls to the sales guys on mobile phones. Our firewall check is good. One user is using Android and another is using IOS. When we uninstall the mobile apps, phones work fine, but the sales guys want to take the calls anywhere. Any ideas where to start? We are on v20 Update 4 487 Release

 

[Alex Renard]

It’s probably something with PUSH or network settings. First, check if PUSH is enabled in Settings > PBX > 3CX App. If the sales guys are remote, make sure they’re using SBC or the Tunnel instead of STUN, which can be unreliable. Even if the firewall check looks good, double-check that SIP ALG is off—it causes all sorts of weird issues. Also, try deleting and reprovisioning the apps using the 3CX welcome email. See if the drops happen more on Wi-Fi or mobile data, and make sure the apps are fully updated. If it’s still a problem, check the logs for errors or have them try the Web Client/PWA as a workaround.