40-486: NetBIOS ( / ˈ n ɛ t b aɪ ɒ s / ) is an acronym for Network Basic Input/Output System . It provides services related to the session layer of the OSI model allowing applications on separate computers to communicate over a local area network . As strictly an API , NetBIOS is not a networking protocol . Operating systems of the 1980s (DOS and Novell Netware primarily) ran NetBIOS over IEEE 802.2 and IPX/SPX using
80-488: A DNS server. (It is also possible to operate many TCP/IP-based applications, including the three listed above, using only IP addresses, but this is not the norm.) Under Windows, the node type of a networked computer relates to the way it resolves NetBIOS names to IP addresses . This assumes that there are any IP addresses for the NetBIOS nodes, which is assured only when NetBIOS operates over NBT; thus, node types are not
120-650: A NetBIOS Service on a TCP/UDP Transport: Detailed Specifications"). The NBT protocol was developed in order to "allow an implementation [of NetBIOS applications] to be built on virtually any type of system where the TCP/IP protocol suite is available," and to "allow NetBIOS interoperation in the Internet." After the PS/2 computer hit the market in 1987, IBM released the PC LAN Support Program, which included
160-422: A checkpoint has been committed by the application, and after an application crash or a power failure, a resynchronization can be used to indicate that the application has recovered from a checkpoint and the transmission can be resumed from that point. This may also be used to interrupt / resume a dialogue at any time, not due to an application failure, but as planned by the application. The application may interrupt
200-457: A dialogue, start another dialogue in the same session, and resume the previous dialogue in the same session or in another session. The session layer may also provide explicit support for managing multiple interruptible dialogues over one or more sessions. These dialogues are called activities . Activities can be interrupted and resumed explicitly. Compared to implicitly interrupting and resuming dialogues by resynchronization, activity support gives
240-676: A driver offering the NetBIOS API. There is some confusion between the names NetBIOS and NetBEUI. NetBEUI originated strictly as the moniker for IBM's enhanced 1985 NetBIOS emulator for Token Ring. The name NetBEUI should have died there, considering that at the time, the NetBIOS implementations by other companies were known simply as NetBIOS regardless of whether they incorporated the API extensions found in Token Ring's emulator. For MS-Net, however, Microsoft elected to name its implementation of
280-481: A length field to each SMB message; this is necessary because TCP only provides a byte-stream service with no notion of message boundaries.) In order to start sessions or distribute datagrams, an application must register its NetBIOS name using the name service. NetBIOS names are 16 octets in length and vary based on the particular implementation. Frequently, the 16th octet, called the NetBIOS Suffix, designates
320-527: A positive-acknowledgment (ACK) or negative-acknowledgment (NAK) response. A NAK will prompt retransmission of the data. Sessions are closed by the non-initiating computer by sending a close request. The computer that started the session will reply with a close response which prompts the final session closed packet. When NetBIOS is run in conjunction with Internet protocols (e.g., NBT), each computer may have multiple names: one or more NetBIOS name service names and one or more Internet host names. The NetBIOS name
360-544: A property of NetBIOS per se but of interaction between NetBIOS and TCP/IP in the Windows OS environment. There are four node types. The node type in use is displayed by opening a command line and typing ipconfig /all . A Windows computer registry may also be configured in such a way as to display "unknown" for the node type. The NetBIOS Suffix, alternately called the NetBIOS End Character (endchar),
400-477: A sequence of alphanumeric characters. The following characters are explicitly not permitted: \/:*?"<>| . Since Windows 2000, NetBIOS names also had to comply with restrictions on DNS names: they cannot consist entirely of digits, and the hyphen ("-") or full-stop (".") characters may not appear as the first or last character. Since Windows 2000, Microsoft has advised against including any full-stop (".") characters in NetBIOS names, such that applications can use
440-524: A session-layer protocol is the OSI protocol suite session-layer protocol, also known as X.225 or ISO 8327. In case of a connection loss this protocol may try to recover the connection. If a connection is not used for a long period, the session-layer protocol may close it and re-open it. It provides for either full duplex or half-duplex operation and provides synchronization points in the stream of exchanged messages. Other examples of session layer implementations include Zone Information Protocol (ZIP) –
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#1732790250036480-481: A technical reference book from IBM, the NetBIOS API specification has become a de facto standard in the industry despite originally supporting a maximum of only 80 PCs in a LAN. This limitation was generally overcome industry-wide through the transition from NBF to NBT, under which, for example, Microsoft was able to switch to Domain Name System (DNS) for resolution of NetBIOS hostnames , having formerly used
520-416: Is 16 ASCII characters, however Microsoft limits the host name to 15 characters and reserves the 16th character as a NetBIOS Suffix. This suffix describes the service or name record type such as host record, master browser record, or domain controller record or other services. The host name (or short host name) is specified when Windows networking is installed/configured, the suffixes registered are determined by
560-531: Is released, the underlying transport connection may be reused for another session connection. Also, a session connection may make use of multiple consecutive transport connections. For example, if, during a session, the underlying transport connection has a failure, the session layer may try to re-establish a transport connection to continue the session. The session layer may provide three different dialogue types - two way simultaneous (full-duplex), two way alternate (half-duplex), and one way (simplex). It also provides
600-416: Is responsible for error detection and recovery. In NBT , the datagram service runs on UDP port 138. The datagram service primitives offered by NetBIOS are: Session mode lets two computers establish a connection, allows messages to span multiple packets, and provides error detection and recovery. In NBT , the session service runs on TCP port 139. The session service primitives offered by NetBIOS are: In
640-414: Is the 16th character of a NetBIOS name and indicates service type for the registered name. The number of record types is limited to 255; some commonly used values are: For unique names: For group names: The following table shows a brief history of NetBIOS and its related protocols. SMB was the main protocol that used NetBIOS. SMB enables Windows File and Printer Sharing. Session layer In
680-568: The AppleTalk protocol that coordinates the name binding process, and Session Control Protocol (SCP) – the DECnet Phase IV session-layer protocol. Within the service layering semantics of the OSI network architecture, the session layer responds to service requests from the presentation layer and issues service requests to the transport layer . At the minimum, the session layer allows
720-530: The NetBIOS Frames (NBF) and NetBIOS over IPX/SPX (NBX) protocols, respectively. In modern networks, NetBIOS normally runs over TCP/IP via the NetBIOS over TCP/IP (NBT) protocol. NetBIOS is also used for identifying system names in TCP/IP (Windows). NetBIOS is an operating system-level API that allows applications on computers to communicate with one another over a local area network (LAN). The API
760-1188: The application layer protocols. TCP/IP's layers are descriptions of operating scopes (application, host-to-host, network, link) and not detailed prescriptions of operating procedures or data semantics. IBM PS Look for IBM PS on one of Misplaced Pages's sister projects : [REDACTED] Wiktionary (dictionary) [REDACTED] Wikibooks (textbooks) [REDACTED] Wikiquote (quotations) [REDACTED] Wikisource (library) [REDACTED] Wikiversity (learning resources) [REDACTED] Commons (media) [REDACTED] Wikivoyage (travel guide) [REDACTED] Wikinews (news source) [REDACTED] Wikidata (linked database) [REDACTED] Wikispecies (species directory) Misplaced Pages does not have an article with this exact name. Please search for IBM PS in Misplaced Pages to check for alternative titles or spellings. You need to log in or create an account and be autoconfirmed to create new articles. Alternatively, you can use
800-461: The article wizard to submit a draft for review, or request a new article . Search for " IBM PS " in existing articles. Look for pages within Misplaced Pages that link to this title . Other reasons this message may be displayed: If a page was recently created here, it may not be visible yet because of a delay in updating the database; wait a few minutes or try the purge function . Titles on Misplaced Pages are case sensitive except for
840-634: The LAN segment-compartmentalized NBF protocol itself to resolve such names in Windows client-server networks . NetBIOS provides three distinct services: (Note: SMB , an upper layer, is a service that runs on top of the Session Service and the Datagram service, and is not to be confused as a necessary and integral part of NetBIOS itself. It can now run atop TCP with a small adaptation layer that adds
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#1732790250036880-507: The NBF protocol "NetBEUI" – naming its implementation of the transport protocol after IBM's enhanced version of the API. Consequently Microsoft file and printer sharing over Ethernet often continues to be called NetBEUI, with the name NetBIOS commonly used only in reference to file and printer sharing over TCP/IP . More accurately, the former is NetBIOS Frames (NBF), and the latter is NetBIOS over TCP/IP (NBT). Since its original publication in
920-624: The NetBIOS API for its MS-Net networking technology. As in the case of IBM's Token Ring, the services of Microsoft's NetBIOS implementation were provided over the IEEE 802.2 Logical Link Control layer by the NBF protocol. However, the MS-Net was only delivered to OEMs , and it was actually not a complete product, nor was it ready to communicate on the network in the form it was distributed. It lacked any implementation of OSI Layers 1 to 4 ( Physical , Data link , Network and Transport Layers) and an OEM
960-584: The System Properties dialog box. There may also be connection-specific suffixes which can be viewed or changed on the DNS tab in Control Panel → Network → TCP/IP → Advanced Properties. Host names are used by applications such as telnet , ftp , web browsers , etc. To connect to a computer running the TCP/IP protocol using its name, the host name must be resolved into an IP address , typically by
1000-406: The application simpler control of these dialogues. The TCP/IP reference model does not concern itself with the OSI model's details of application or transport protocol semantics and therefore does not consider a session layer. OSI's session management in connection with the typical transport protocols (TCP, SCTP), is contained in the transport-layer protocols, or otherwise considered the realm of
1040-465: The base NetBIOS API created by Sytek with, among other things, the ability to deal with the greater node capacity of Token Ring. A new networking protocol, NBF , was simultaneously produced by IBM to allow its NetBEUI API (their enhanced NetBIOS API) to provide its services over Token Ring – specifically, at the IEEE 802.2 Logical Link Control layer. In 1985, Microsoft created its own implementation of
1080-512: The case). Generally a computer running Internet protocols (whether it is a Windows machine or not) usually has a host name (also sometimes called a machine name). Originally these names were stored in and provided by a hosts file but today most such names are part of the hierarchical Domain Name System (DNS). Generally the host name of a Windows computer is based on the NetBIOS name plus the Primary DNS Suffix, which are both set in
1120-587: The company's own emulation of the NetBIOS API. Its services were encapsulated within NetWare's IPX/SPX protocol using the NetBIOS over IPX/SPX (NBX) protocol. In 1987, a method of encapsulating NetBIOS in TCP and UDP packets, NetBIOS over TCP/IP (NBT), was published. It was described in RFC 1001 ("Protocol Standard for a NetBIOS Service on a TCP/UDP Transport: Concepts and Methods") and RFC 1002 ("Protocol Standard for
1160-425: The data flow, and a resynchronization may be used to reset the transmission to start from a new timestamp. For example, if the video stream lags behind the audio stream too much, the receiving side may issue a resynchronization request on the video stream, restarting its transmission from a later timestamp. This may also be used by the application to do checkpointing. Synchronization points can be used to indicate that
1200-509: The individual services supplied by the host. In order to connect to a computer running TCP/IP via its NetBIOS name, the name must be resolved to a network address . Today this is usually an IP address (the NetBIOS name to IP address resolution is often done by either broadcasts or a WINS Server – NetBIOS Name Server). A computer's NetBIOS name is often the same as that computer's host name (see below), although truncated to 15 characters, but it may also be completely different. NetBIOS names are
1240-499: The mechanisms to negotiate the type of the dialogue, and controls which side has the "turn" or "token" to send data or to perform some control functions. Dialogue control is not implemented in TCP/IP, and is left to the application layer to handle, if necessary. In the widely-used HTTP/1.1 protocol, the client and the server typically work in a half-duplex way. HTTP/1.1 also supports HTTP pipelining for full-duplex operation, but many servers/proxies couldn't handle it correctly, and there
NetBIOS - Misplaced Pages Continue
1280-411: The original protocol used to implement NetBIOS services on PC-Network, to establish a session, the initiating computer sends an Open request which is answered by an Open acknowledgment. The computer that started the session will then send a Session Request packet which will prompt either a Session Accept or Session Reject packet. During an established session, each transmitted packet is answered by either
1320-429: The presence of a full-stop to distinguish domain names from NetBIOS names. The Windows LMHOSTS file provides a NetBIOS name resolution method that can be used for small networks that do not use a WINS server. A Windows machine's NetBIOS name is not to be confused with the computer's Internet host name (assuming that the computer is also an Internet host in addition to being a NetBIOS node, which need not necessarily be
1360-475: The seven-layer OSI model of computer networking , the session layer is layer 5 . The session layer provides the mechanism for opening, closing and managing a session between end-user application processes, i.e., a semi-permanent dialogue. Communication sessions consist of requests and responses that occur between applications. Session-layer services are commonly used in application environments that make use of remote procedure calls (RPCs). An example of
1400-404: The two sides to establish and use a connection, called a session, and allows orderly release of the connection. In the OSI model, the transport layer is not responsible for an orderly release of a connection. Instead, the session layer is responsible for that. However, in modern TCP/IP networks, TCP already provides orderly closing of connections at the transport layer. After a session connection
1440-410: The type of resource, and can be used to tell other applications what type of services the system offers. In NBT , the name service operates on UDP port 137 (TCP port 137 can also be used, but rarely is). The name service primitives offered by NetBIOS are: Internet Protocol Version 6 (IPv6) are not supported by the NetBIOS name resolution protocol. Datagram mode is connectionless ; the application
1480-642: Was created in 1983 by Sytek Inc . for software communication over IBM PC Network LAN technology. On IBM PC Network , as an API alone, NetBIOS relied on proprietary Sytek networking protocols for communication over the wire. In 1985, IBM went forward with the Token Ring network scheme and produced an emulator of Sytek's NetBIOS API to allow NetBIOS-aware applications from the PC-Network era to work over IBM's new Token Ring hardware. This IBM emulator, named NetBIOS Extended User Interface (NetBEUI), expanded
1520-467: Was expected to provide these implementations (in the form of a NetBIOS part) to make its version of MS-Net a complete and ready to use product. MS-Net accessed the network through the Microsoft's own variant of NetBIOS, which was split into two parts - the lower level part that OEMs had to provide implemented the NetBIOS calls that depended on layers 1-4, while the higher level part, provided by Microsoft,
1560-450: Was hardware- and protocol-independent. This NetBIOS implementation supported the full NetBIOS API, but was called by invoking x86 interrupt 0x2A, instead of IBM's standard interrupt 0x5C. The reliance on OEMs to implement parts of NetBIOS had the unfortunate side effect that different OEM versions of MS-Net and NetBIOS generally weren't able to communicate with one another. In 1986, Novell released Advanced Novell NetWare 2.0 featuring
1600-537: Was no dialogue negotiation mechanism to check whether full-duplex is usable or not, so its support was eventually dropped by most browsers. The session layer may also allow the two sides to insert synchronization points into the dialogue, and allow them to do a resynchronization , which aborts the current transmission, sets the synchronization point to a certain value, and restarts transmission from that point. This may be used in real-time audio/video transmission. Synchronization points can be used to insert timestamps to
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