Error 503 / Server Unavailable / Could Not Connect to Server

If you receive one of the following errors:

• Error 503
• Server Unavailable
• Could Not Connect to Server

Then you may be experiencing a connectivity problem that is preventing your phone from connecting to your MaxoTel service.

This error may be caused by the following:

1. Incorrectly configured phone (please double check your settings with our Configuration Guides)
2. A firewall or antivirus software on your PC or Laptop (if using SoftPhones)
3. Disable any VPN services on your PC or laptop (if using SoftPhones)
4. SIP ALG configuration on your router (see: SIP ALG)
5. Firewall configuration on your router (see: SIP Requirements)
6. Check whether your ISP is blocking SIP (see: Internet Service Providers Blocking SIP)

If the above steps do not resolve the issue, please contact our support team for further assistance.