Yealink t29G | 5 seconds ring delay

[gmanual]

This problem is caused by bad DNS.

To the admin that keeps deleting my reply:

1. Google "yealink delay ring"
2. See that this thread is the top result.
3. Assume that I didn't spend days troubleshooting this issue without trying the factory reset, as suggested above.
4. Know that once I found the issue, I waited patiently 24 hours for my forum account to allow me to post.
5. Assume that other people with a similar issue will want to know the cause of the problem.