Are the renew subscription requiere that webhook respond within 1000 milliseconds because I'm getting a unreachable error? Maybe you should put more time because this depend on a lot of thing that we don't always have control. I think that 5000 should be enough for everyone. Or maybe we should be able to set "never expire"
The issue is not about the expiry event but with the 1000 sec too short for us. So if the API try to renew the webhook, but got an "unreachable" error because 1000sec is over, I will get the same problem.
I have do some test with some other API endpoint and your API, and a lot of time, this can take more than 1000 ms. So I think this is very very restrictive and should be raise. I never reach 3000ms, So I think this is enough. Sometimes, I reach a little bit over 2000.
The 1000ms requirement should be for general response, e.g. creating a webhook (verification) and events. It's interesting that you are only seeing this during subscription renewal. If this is the case, you can proactively renew the subscription since you know the expiration time. When you see a verification header you can have your server respond immediately without calling the other API endpoint.
We are looking into non-expiring webhooks but the above may be able to solve your situation now.
Finally. My test doesn't seem to give result. Always have the
"message": "WebHook is not reachable",
"message": "WebHook is not reachable"
error and this is exactly the same thing when I register the webhook the first time and this is not fast enough for ringcentral. Need to retry a lot of time until this work. But renewing make the webhook deleted if fail and I need to register it again...