Is it 32 bit, or 64 bit or 128 bit or bigger?
['https://Stackoverflow.com/questions/861911', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/106866/']
It's neither int nor guid; from the [MSDN help file](http://msdn.microsoft.com/en-us/library/system.web.sessionstate.sessionidmanager.aspx)...

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> The ASP.NET session identifier is a randomly generated number encoded into a 24-character string consisting of lowercase characters from a to z and numbers from 0 to 5.
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Because it's generated as a [System.Guid](http://msdn.microsoft.com/en-us/library/system.guid(VS.90).aspx) Valuetype, it's a 128-bit integer, which is 16 bytes.