The NetBIOS interface was developed by Sytec Inc. for IBM in 1983 and operated over proprietary Sytec protocols on IBM's PC Network which is broadband local area network.
The original protocols have been superseded by the implementation over IEEE 802.2 networks; the packet structures for the IBM PC network are given here for reference.
| Name Claim / Cancel | Name Response |
|---|---|
| < - 1 Octet (8 bits) -> | < - 1 Octet (8 bits) -> |
| Start Deliminator = 0x7E | Start Deliminator = 0x7E |
| Destination Address 6 octets | Destination Address 6 octets |
| Source Address 6 octets | Source Address 6 octets |
| Length 2 octets | Length 2 octets |
| Value 0x5000 | Value 0x4000 |
| Claim 0x10 Cancel 0xA0 | Value 0x30 |
| No Packets to accept N | No Packets to accept N |
| Connection id 2 octets | Connection id 2 octets |
| Value 0x02 | Undefined |
| Value 0x02 | Undefined |
| Undefined | Reason NAK |
| Undefined | Undefined |
| Value 0x04 | Value 0x04 |
| Value 0x00 | Value 0x00 |
| Undefined 4 octets | Undefined 4 octets |
| Value 0x10 | Value 10h |
| Value XXh | Value XXh |
| Value 0x00 | Value 0x00 |
| Value 0x00 | Value 0x00 |
| ASCII Dest name 16 octets | ASCII Dest name 16 octets |
| Prev net con id | Dest node conn id |
| Prev net con id | Dest node conn id |
| Retransmit count | CRC 4 octets |
| Retransmit count | |
| Source node con id | |
| Source node con id | |
| Dest id 6 octets | EOF 0x7E |
| Source id 6 octets | |
| Prev node id 6 octets | |
| CRC 4 octets | |
| EOF 0x7E |
| Name Query | Session Request | Session Accept | Session | Acknowledgement |
|---|---|---|---|---|
| < - 1 Octet (8 bits) -> | < - 1 Octet (8 bits) -> | <- 1 Octet (8 bits) -> | < - 1 Octet (8 bits) -> | < - 1 Octet (8 bits) -> |
| Start Deliminator = 0x7E | Start Deliminator = 0x7E | Start Deliminator = 0x7E | Start Deliminator = 0x7E | Start Deliminator = 0x7E |
| Destination Address 6 octets | Destination Address 6 octets | Destination Address 6 octets | Destination Address 6 octets | Destination Address 6 octets |
| Source Address 6 octets | Source Address 6 octets | Source Address 6 octets | Source Address 6 octets | Source Address 6 octets |
| Length 2 octets | Length 2 octets | Length 2 octets | Length 2 octets | Length 2 octets |
| Value 0x5000 | Value 0x0040 | Value 0x0040 | Value 0x4000 | Value 0x4000 |
| Value 0x10 | 0x00 - 0x07 No Poll 0x80 -0x0F Send return packet | 0x00 - 0x07 No Poll 0x80 -0x0F Send return packet | 0x00 - 0x07 No Poll 0x80 -0x0F Send return packet | 0x40 - 0x47 No Poll 0x48 -0x4F Send return packet |
| No Packets to accept 0?h | No Packets to accept 0?h | No Packets to accept 0?h | No Packets to accept 0?h | No Packets to accept N |
| Connection id 2 octets | Connection id 2 octets | Connection id 2 octets | Connection id 2 octets | Connection id 2 octets |
| Value 0x02 | Ses Seq No | Ses Seq No | Ses Seq No | Ses Seq No |
| Value 0x02 | ACK Seq No | ACK Seq No | ACK Seq No | ACK Seq No |
| Undefined | Value 0x00 | Value 0x00 | 0x80-0xF0 End message | Undefined |
| Undefined | Value 0x01 | Value 0x02 | DATA N octets | Dest Node Con |
| Value 0x10 | Response packet size | Response packet size | Dest Node Con | |
| Value 0x00 | Response packet size | Response packet size | CRC 4 octets | |
| Undefined | Value 0x00 | Dest node conn id | ||
| Undefined | Value 0x00 | Dest node conn id | ||
| Undefined | Value 0x10 | CRC 4 octets | ||
| Undefined | Value 0x10 | EOF 0x7E | ||
| Value 0x10 | ASCII Source name | |||
| Value 0xXX | ASCII Source name | |||
| Value 0xXX | ASCII Source name | EOF 7Eh | ||
| Value 0x10 | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | Dest node con id | ||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | CRC 4 octets | ||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | |||
| ASCII Dest name | ASCII Source name | EOF 0x7E | ||
| ASCII Dest name | ASCII Dest name | |||
| ASCII Dest name | ASCII Dest name | |||
| ASCII Dest name | ASCII Dest name | |||
| ASCII Dest name | ASCII Dest name | |||
| Prev net con id | ASCII Dest name | |||
| Prev net con id | ASCII Dest name | |||
| Retransmit count | ASCII Dest name | |||
| Retransmit count | ASCII Dest name | |||
| Source node con id | ASCII Dest name | |||
| Source node con id | ASCII Dest name | |||
| Dest id | ASCII Dest name | |||
| Dest id | ASCII Dest name | |||
| Dest id | ASCII Dest name | |||
| Dest id | ASCII Dest name | |||
| Dest id | ASCII Dest name | |||
| Dest id | ASCII Dest name | |||
| Source id | Dest node conn id | |||
| Source id | CRC | |||
| Source id | CRC | |||
| Source id | CRC | |||
| Source id | CRC | |||
| Source id | EOF 0x7E | |||
| Prev node id | ||||
| Prev node id | ||||
| Prev node id | ||||
| Prev node id | ||||
| Prev node id | ||||
| Prev node id | ||||
| CRC | ||||
| CRC | ||||
| CRC | ||||
| CRC | ||||
| EOF 0x7E |
| Datagram |
|---|
| < - 1 Octet (8 bits) -> |
| Start Deliminator = 0x7E |
| Destination Address 6 octets |
| Source Address 6 octets |
| Length 2 octets |
| Value 0x5100 |
| Value 0x100 |
| No Packets to accept 0x01 |
| Value of 0x1010 |
| Value 0x00 |
| Value 0x00 |
| ASCII Source name 16 octets |
| ASCII Dest name 16 octets |
| Data variable |
| Data N octets |
| Retransmit count 2 octets |
| Source node connect id 2 octets |
| Dest id 6 octets |
| Source id 6 octets |
| Prev node id 6 octets |
| CRC 4 octets |
| EOF 0x7E |
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