+ @vss_type - 0: use ASCI vpn_id; 1: use oui/vpn_index; 255: global vpn
+ @vpn_ascii - null terminated ASCII VPN ID up to 128 characters
+ @param oui - first part of rfc2685 vpn id, 3 bytes oui
+ @param vpn_index - second part of rfc2685 vpn id, 4 bytes vpn index