Jamie Thain wrote a very good essay on network protocols. I want to partition
things that are related to NETBIOS, since it is that mixing what often leads to
misunderstanding of MS net communications.
There are three things that people call NETBIOS/NetBEUI:
1. Network+Transport protocol layers. These were developed for the Token Ring
PC implemenation. The software was burned into ROM chips on the network cards
and mapped into the computers address space. That's where name NETBIOS came
from. This protocol is not routable, and designed to work on a single LAN
segment. I'll call it NETBIOS(1).
2. NETBIOS(2) is also an API specification, just like BSD sockets. Note the big
difference: this set of API has nothing to do with the underlaying implementation.
When you open NETBIOS(2) session using these API, it may be NETBIOS(1), TCP or
SPX session in network look. You do not generally even want to know what protocol
pipes data. You cannot say 'routable' or 'unroutable' regarding _this_ NETBIOS.
3. SMB, the core protocol of MS network, is also often illegally referred to as
NETBIOS. SMB is a specification of packet formats, that are sent between client
and server using any sequential error free delivery method. So NETBIOS(1), TCP,
SPX and just postmen go (later require some timeout adjustment ;). Actually,
MS network uses NETBIOS(2) to deliver SMB packets, but this does not not mean
NETBIOS(1): it can be bound to any stream oriented protocol.
So, when someone says netbios, you need to know what of netbioses that netbios is.
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< Kirill M Katsnelson, Software Engineer, Owner of Elipromm Priv Co >
< EMAIL: kkm@xkis.nnov.su HOME PAGE: http://www.bhs.com/kkm/ >
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