Specify packet format that is sent to RADIUS server. The value
SHOULD be set the same as the value of corresponding server.
1 (onePacket) - Specify 'one-packet' as the unit of packet.
2 (kiloPacket) - Specify 'kilo-packet' as the unit of packet.
3 (megaPacket) - Specify 'mega-packet' as the unit of packet.
4 (gigaPacket) - Specify 'giga-packet' as the unit of packet.
Default value is 1.