Call History Sync

Cymbus stores a synchronized call log history for each user. Here's how it works:

1. Setup. The first time a user logs in to the Cymbus app, Cymbus deletes the previous call history saved locally on the user's device and replaces it with a synchronized call log history.
   
   
2. Log. All new calls to Cymbus are posted to the online call log server.
   
   
3. Sync. When the user logs in to Cymbus from a second device, the call logs are synchronized between both devices. Cymbus downloads the call logs in small increments as the user scrolls down the list or tries to view older call logs.
   
   
4. Merge. When the user receives an incoming call while more than one device is running Cymbus, the log server merges the call logs coming from both devices into one record.
   
   
5. Delete. When the user deletes a call log from one device, the log is deleted from both the log server and the user’s other device.
   
   
6. Retry. If the log server is not available for sync, Cymbus retries later until it successfully connects.