packet analysis

[phirestalker]

well I have a free packet analyzer now, but it only recognizes the base protocols up to TCP or UDP, which kind of tells me what the packet is missing when I try to use UDPClient to send a net message, but I need to know what each part is like Wildpackets' EtherPeek tells me, does anyone know of a free packet analyzer that "knows" as much as etherpeek, or maybe a PDF or document that takes apart a NETBIOS packet and explains it??

Please help