If I had to pick a poison I would implement a SQLCLR method (of my own) before I would use xp_cmdshell for this. That said, at the end of the day none of it belongs in T-SQL.

Rolling your own SQLCLR objects to confirm a ping was possible or get the ping round trip time would be trivial. The SQL# methods are thin wrappers over methods on the .NET Ping class built into .NET 2.0.

Ping.Send Method (String, Int32, Byte[], PingOptions)