When using SIP protocol one way or missing auido issues mostly appear due to configuration problems. The issues usually appear if the configuration is not adjusted accordingly to the wireless or 3g/4g network.
In most cases this can be resolved by altering the account configuration.
Run Zoiper for Android and go to Config. Select Accounts and click on the affected account.
Scroll down to NetworkSettings.
Try enabling or disabling RPORT for signalling, save
the changes and try to make a call. If the issue persists, open the
Network Settings again and activate or deactivate STUN*. Save the changes and make a test call.
* By default, Zoiper for Android is using stun.zoiper.com. Your provider might have their own prefferred STUN server. If the issue persists, open the Network Settings once again and try enabling or disabling RPORT for media. Save the changes and make a test call.
Try different combinations of these settings to achieve better results. One such combination may be the following.
Other causes for the missing audio issue are:
- A limitation issued by your provider:
Your provider could be filtering or altering the network packets. It is possible to bypass the restrictions by using IAX, TCP/TLS, non standard ports or VPN tunnels, depending on the way of blocking. Any of these would require support on the server side. You will need to contact your voip provider or VoIP System Administrator for more assistance.
To change the transport type for your account you need to run Zoiper for Android, go to Config, then go to Accounts, select your account and scroll down to Network Settings. Change the transport type to UDP, TLS or TCP, according to your provider’s recommendation.
- Your wi-fi access point is filtering or rewriting the network packets:
Some wifi routers’ implementation of the SIP ALG filter is broken. Most of the reported cases are with NetGEAR devices. To disable the broken filter you will need to login on to the device with an administratice account and disable the SIP ALG filter. It is often named STATEFUL SIP INSPECTION. Depending on the model of your device this option can be a bit hard to locate. Please review your device’s documentation.
In case you do not have access to your router’s admin panel, contact your ITSP and your VoIP System Administrator for further assistance.
- You have a firewall installed on your Android device or on your router / network
Please try disabling or adjusting the firewall and try to make a
call. If using Zoiper with WiFi, please make sure that the routing
device is not blocking the ports used by Zoiper. Zoiper is using the
following ports:SIP port is 5060IAX port is 4569 UDPRTP port is between 32000 and 65535 UDP
Default STUN vallues:
Server hostname / IP :stun.zoiper.com Port :3478 UDP / TCP
Refresh period : 30
- Your Android device has a problem with the audio driver
Start your Zoiper for Android, go to Config, select Audio and scroll to the bottom of the page. Change the Audio Driver to “External Java Driver”.