Value,Group Type,Reference
0,Reserved,
1,MODP (modular exponentiation group),[RFC2409]
2,ECP  (elliptic curve group over GF[P]),[RFC2409]
3,EC2N (elliptic curve group over GF[2^N]),[RFC2409]
4-65000,Unassigned,
65001-65535,Reserved for private use,