@@PACK_RECEIVED Returns the total input packets read from the network since the SQL Server instance was last : PACK_RECEIVED « System Settings « SQL Server / T-SQL Tutorial

1. SQL Server / T-SQL Tutorial
2. System Settings
3. PACK_RECEIVED

started. You can monitor whether the number increments or stays the same, thus surmising if there is a network 
availability issue.
3>
4> SELECT 'PackReceived', @@PACK_RECEIVED
5> GO

------------ -----------
PackReceived        6457

(1 rows affected)