If the Updates page does not display in the Switchvox Admin interface, it is likely caused by a communication issue between your Switchvox and the updates server located at Digium. To check for issues you can take a packet capture using the instructions located here, then follow the steps below:
Using Wireshark, sort by the IP address of the Updates server (64.87.27.229)
Look in the packets for traffic to and from the server. It should look similar to the below:
If you see traffic to the Updates server but no traffic back, it would indicate that there is some networking component blocking access from Digium. All traffic should be HTTP traffic over ports 80 or 443 and you can troubleshoot your local networking equipment to locate the source of the block.