How do I interpret VSAs in an IAS-formatted NPS log file?

I see these VSAs in my request to the RADIUS server:

AVP: l=40 t=Vendor-Specific(26) v=Microsoft(311)
VSA: l=34 t=MS-Machine-Name(50): WIN4ABC.xyz.net

AVP: l=12 t=Vendor-Specific(26) v=Microsoft(311)
VSA: l=6 t=MS-Network-Access-Server-Type(47): Terminal-Server-Gateway(1)

I believe NPS logs them as:

8138,WIN4ABC.xyz.net
8132,1