how to connect computer to domain server

1-   click start -------->control Panel -------->system

2-    On the " Network Identification tab" click "Properties".

3-    Under "Member of" click "Domain" type the name of the windows small bussiness domain, and click "OK".

4-    When prompted provide a user name and password.

5-    Click "OK" to close the "System Properties"  dialog box and restart your computer.

What Is OSI

                In the early 1980s, the International Standards Organization (ISO) saw the need ;to develop a network model to  help  vendors create interoperable network solutions.  It developed what is now known as the open System Interconnection (OSI) reference model.  Even though other networking models have been created, they often are related back to the OSI reference model when vendors want to provide education about their products.

What is the Open System

                The concept of derived from a need standardization.  Many people have encountered a situation in which they must choose between competing products.  The major problem is that if you buy BigCorp’s XYZ product, you are tied to that product as your networking solution.

                TCP/IP is good example of an o pen system for a protocol suite.  Through the use of RFCs, all TCP/IP standards are fully documented.  They have been designated as required or elective components to be included in a vendor’s implementation of TCP/IP. The goal of TCP/IP is to provide connectivity between heterogeneous systems.  You might have to make some choices about how you implement the connectivity. By using TCP/IP, however, you know you have an underlying framework that is available on most platform.

                Be careful with the term open systems.  Many times it is bandied about as the end-all and be-all almost a religion.  Competing products drive the market to come up with better solutions.  If there is absolutely no difference between product A and Product B, why would you not always choose the cheaper of the two products? 

Asynchronous Transfer Mode (ATM)

                Asynchronous Transfer mode uses advanced technology to segment data into cells at high speeds.  Each cell is fixed length, consisting of 5 byte of header information and 48 bytes of payload data.  The use of a fixed-length packet results in higher transfer speeds because the network    spends less time processing incoming data It also helps in planning application bandwidth.  Cells cross the ATM network by the passing through devices known as ATM switches.  These switches analyze header information to switch the cell to the next ATM switch that ultimately leads to the destination network.  ATM enables more than one computer to transmit at the same time through the use of multiplexers. 

                The request includes the ATM address of the Target ATM device as well as quality of service (Qos) parameters.  The QOS parameters essentially set minimum guidelines stat must be met for transmission.  They include values for peak bandwidth, average sustained bandwidth, and burst size, if the actual traffic flow does not meet the QOS specifications, the cell can be marked as discard-eligible.  This means any ATM switch that handles the cell can drop the cell in periods of congestion.  At each switch, the signaling request is reassembled and examined.  If the switch table has an entry of the destination ATM device and the ATM switch can accommodate the QOS requested for the connection, it forwards the cell to the next ATM switch.  When the cell to the next ATM switch. When the cell signaling requested for the connection, it forwards the cell to the next ATM switch.  When the cell signaling request reaches the destination endpoint, it responds with an accept message.

                The wraps up the basics of the various network types that can be implemented for your network.  The next section looks at a concept, Open Systems, that allows standardized protocols to be developed that provide network connectivity over the networks we deploy.

Frame Relay

                Network communications have moved toward digital and fiber – optic environments.  There is less need for the error checking found in the X.25 protocol.  As the result, many large corporations use Frame Relay provide fast, variable-length packet-packet-switching over digital networks. Frame Relay includes a cyclic redundancy check (CRC) algorithm that can detect whether a packet is corrupted and can discard it.  It does not; however ask for retransmission of the data.  It leaves that up to higher levels that up to higher levels of the protocol.

                Frame Relay uses permanent virtual circuits (PVCs) so the entire path between two hosts is known from end to end.  This creates an optimal network environment in which the path between two hosts is predetermined.   Instead of always having to calculate the best path to remote host, the PVC has predetermined that route.  In addition, because the hosts are connected using a common frame relay network, packets do not have to be fragmented due to differing Maximum Transmission units (MTUs) The MTU is the largest packet size that canbe used on a network segment.  Frame relay networks all have a same MTU, removing the issues with differing MTUs.

                Frame Relay also includes the following local management interface (LMI) extensions:

·         Virtual circuit status messages provide information about PVC integrity.  They report the addition of any new PVCs and the deletion of existing PVCs.  These status messages prevent hosts from sending messages to a PVC that has ceased to exist.

·         Multicasting is an optional LMI extension that enables a host to send a single frame destined for multiple recipients.  This reduces overall network traffic because a single frame can be sent to multiple hosts instead of one message per host.

·         Global addressing provides globally significant connection identifiers.  Frame Relay uses data link connection identifiers (DLCIs) to identify a circuit ID.  When global addressing is implemented, each connection has a globally unique ID.  This ID is known to all other connections.

If Winnipeg must send a frame to Minneapolis, Winnipeg places a value of 40 in the DLCI field and sends the frame into the Frame Relay network.  When the frame arrives in Minneapolis, the network changes the DLCI field contents to 10.  This shows that the frame came from the Winnipeg network.  This addressing scheme enables the Wan to function using the same methods as a LAN.

·         Simple flow control provided an XON/XOFF flow-control mechanism.  Frame Relay includes simple congestion-notification messages that enable the network to inform user devices when network resources are approaching a congested state.  The simple flow control LMI extension is provided for devices that cannot use these notification messages and that need some level of flow control.

Packet-Switching Networks-

                Packet switching network enable you to transmit data over an any-to-any connection Sometimes a packet-switched network is described as a mesh network.  When information is transmitted over the network, it is known what path the information will take between the sender and the recipient of t he data.

                The original data is broken into smaller packets.  Each packet is tagged with the destination address and sequence number.  As the packet traverses the network between the source and destination hosts, it travels on the best current path.  This way, if a network link goes down during the transmission of a stream of packets, not all the packets have to be re-sent.  Some of the packets will have found an alternate route when the link went down.

                The following are three common implementations of packet-switching networks:

·         X.25

·         Frame relay

·         Asynchronous transfer mode(ATM)

X.25 Networks-

                X.25 is developed in the 1970s to provide users with WAN capabilities over public data networks.  Phone companies developed it, and it attributes are international in nature,  It is administered by an agency of the United Nations called the International Telecommunications Union (ITU).

                In an X.25 network, a host calls another host tyo request a communications session.  If the call is accepted, the two systems. Can begin a full-duplex information transfer. Either host can terminate the session.

                A point –to-point connection takes place between data terminal equipment (DTE) at the client site and data circuit-terminating equipment (DCE) at the carries’        facilities.  The DTE is connected to the DCE through a translation device known as a packet assembler/disassemble (PAD). The DCE connects to packet switching exchanges (PSEs), more commonly known as switches.  The switches interconnect with each other until they reach the DCE of the destination host.  This DCE connects to the DTE connects to the DTE of the host complete the communications session.

                 An association known as a virtual circuit accomplishes the end-to-end communication between the two DTEs.  Virtual circuits enable communication between two defined end points to take place through any number of intermediate nodes.  These nodes do not have to be a dedicated portion of the network.  The circuit is not a physical data link; it is bandwidth that can be allocated on demand.  The following are the two types of virtual circuits:

·         Permanent virtual circuits (PVCs)-  PVCs are used for common data transfers known to occur on a regular basis.  Although the route is permanent, the client pays only for the time the line is in use.

·         Switched virtual circuits (SVCs)-  SVCs are used for data transfers that are sporadic in nature.  The connection uses a specified route across the network.  The route is maintained until the connection ceases.