When logging in to VS Connect, you may experience an error stating either "SIP 408" or "SIP 503" followed by "Service Unavailable." A few different reasons could cause this issue. The leading cause is the network you are on not allowing the connection to reach the VanillaSoft server. There are often some steps that you can take to work around this and resolve the issue.
Note: Since all troubleshooting is outside of VanillaSoft, this is not something VanillaSoft supports. All steps suggested are best efforts. For best troubleshooting, please involve your I.T. person, network administrator, or reach out to your internet service provider.
Step 1 -Wireless Internet
For all troubleshooting, wired internet is a requirement as VanillaSoft does not support WiFi for VoIP lines. It might be worth testing a wired connection if you connect to the internet via WiFi. Depending on your network, the security settings in place might be more strict when connected via WiFi than when connected via wired (Ethernet). If you can log in to VS Connect without issues while hardwired, try some of the below steps to see if you can get wireless to work. More information on system requirements can be found in our VanillaSoft VoIP System Requirements article.
Step 2 - Router Setting
Regardless if you are connected to the internet via WiFi or wired, if you have this issue, you may need to change some settings within your router to allow for this type of connection. One of the most common causes is the 'SIP ALG' setting. For best results, the SIP ALG setting should be disabled. Please contact an I.T. person, network administrator, or your internet service provider for more information.
Step 3 - Specified Port
If you disable SIP ALG, you may need to open port 5060 for SIP traffic on your firewall if there is no change. If you are unsure how to do this, it would be best to reach out to an IT person, network administrator, or your internet service provider.