Is the 7-Layer OSI model still valid or has anything changed about it in recent years?
964196
Doesn't the whole concept of 3-tier computing need it to exist?\nApplication layer = business rules - highly important
1147873
Nope. However, Cisco Call Manager 5.0 is said to be able to trunk SIP. Haven't seen it yet though.
940611
Both software and protocols are in the application (7) layer.
1156655
We had an old legacy windows programs. Few Mac client had recently needed to use. So i gave them a solution as Mac OS 10X with RDC. It worked well.
106416
I dug this up in a quick search haven't tested it myself since I use linux.  My quick read suggests that it does pro-logic as well as 5.1.
339913
there are total 8 DMA channels(DMA0 to DMA7).\nexcept DMA4,all other channels are used for i/o devices.\nDMA2 is fixed for floppy drive.\nDMA4 is fixed for cascading from first DMA controller.\nrest are unassigned.
184830
Works just fine either way. Mine is a low speed and I never had to wait long for file exchanges.
162652
The following varieties of SCSI are currently implemented: \n\nSCSI-1: Uses an 8-bit bus, and supports data rates of 4 MBps \nSCSI-2: Same as SCSI-1, but uses a 50-pin connector instead of a 25-pin connector, and supports multiple devices. This is what most people mean when they refer to plain SCSI. \nWide SCSI: Uses a wider cable (168 cable lines to 68 pins) to support 16-bit transfers. \nFast SCSI: Uses an 8-bit bus, but doubles the clock rate to support data rates of 10 MBps. \nFast Wide SCSI: Uses a 16-bit bus and supports data rates of 20 MBps. \nUltra SCSI: Uses an 8-bit bus, and supports data rates of 20 MBps. \nSCSI-3: Uses a 16-bit bus and supports data rates of 40 MBps. Also called Ultra Wide SCSI. \nUltra2 SCSI: Uses an 8-bit bus and supports data rates of 40 MBps. \nWide Ultra2 SCSI: Uses a 16-bit bus and supports data rates of 80 MBps.
852973
RFC 2460 - IPv6 though defines 8 bit traffic class, it doesn't specify any classes like in IPv4. \n\nI think's it's still in research stage and not yet standardised, mostly it will be used like IPv4 where each bit will specify if it's real time traffic or high bandwidth or low cost etc
667212
I believe 10 is the latest version.\n\nThese sites may help.
42555
First you need to know th differnce. To understand the difference between a router and a switch you need to understand the ISO model.\n\nISO/OSI Network Model\nThe standard model for networking protocols and distributed applications is the International Standard Organization's Open System Interconnect (ISO/OSI) model. It defines seven network layers. \n\nLayer 1 - Physical \nPhysical layer defines the cable or physical medium itself, e.g., thinnet, thicknet, unshielded twisted pairs (UTP). All media are functionally equivalent. The main difference is in convenience and cost of installation and maintenance. Converters from one media to another operate at this level. \n\nLayer 2 - Data Link \nData Link layer defines the format of data on the network. A network data frame, aka packet, includes checksum, source and destination address, and data. The largest packet that can be sent through a data link layer defines the Maximum Transmission Unit (MTU). The data link layer handles the physical and logical connections to the packet's destination, using a network interface. A host connected to an Ethernet would have an Ethernet interface to handle connections to the outside world, and a loopback interface to send packets to itself. \n\nEthernet addresses a host using a unique, 48-bit address called its Ethernet address or Media Access Control (MAC) address. MAC addresses are usually represented as six colon-separated pairs of hex digits, e.g., 8:0:20:11:ac:85. This number is unique and is associated with a particular Ethernet device. Hosts with multiple network interfaces should use the same MAC address on each. The data link layer's protocol-specific header specifies the MAC address of the packet's source and destination. When a packet is sent to all hosts (broadcast), a special MAC address (ff:ff:ff:ff:ff:ff) is used. \n\nLayer 3 - Network \nNFS uses Internetwork Protocol (IP) as its network layer interface. IP is responsible for routing, directing datagrams from one network to another. The network layer may have to break large datagrams, larger than MTU, into smaller packets and host receiving the packet will have to reassemble the fragmented datagram. The Internetwork Protocol identifies each host with a 32-bit IP address. IP addresses are written as four dot-separated decimal numbers between 0 and 255, e.g., 129.79.16.40. The leading 1-3 bytes of the IP identify the network and the remaining bytes identifies the host on that network. The network portion of the IP is assigned by InterNIC Registration Services, under the contract to the National Science Foundation, and the host portion of the IP is assigned by the local network administrators, locally by noc@indiana.edu. For large sites, usually subnetted like ours, the first two bytes represents the network portion of the IP, and the third and fourth bytes identify the subnet and host respectively. \n\nEven though IP packets are addressed using IP addresses, hardware addresses must be used to actually transport data from one host to another. The Address Resolution Protocol (ARP) is used to map the IP address to it hardware address. \n\nLayer 4 - Transport \nTransport layer subdivides user-buffer into network-buffer sized datagrams and enforces desired transmission control. Two transport protocols, Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), sits at the transport layer. Reliability and speed are the primary difference between these two protocols. TCP establishes connections between two hosts on the network through 'sockets' which are determined by the IP address and port number. TCP keeps track of the packet delivery order and the packets that must be resent. Maintaining this information for each connection makes TCP a stateful protocol. UDP on the other hand provides a low overhead transmission service, but with less error checking. NFS is built on top of UDP because of its speed and statelessness. Statelessness simplifies the crash
708972
Depends what configuration you have... If you're running on a lower performance computer and you have a lot of apps installed, it will take a while untill the list is filled (it could last a few minutes)...(On my old Duron 700Mhz with 256ram  i had oracle 9i installed and working:D, .NET 2001 and other programming stuff and it took me 5 minutes as I remember until that list was "filled"...).
266666
It doesn't crash nearly as often.\n\nIt has had full support for networking since the 1970s, additionally it supports remote access to Operating System.\n\nIt is fully customizable for a computer's hardware making it very suitable for a large business where every machine has nearly the same hardware.
338401
Interconnection, an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers.\n\nApplication(Layer 7) \nThis layer supports application and end-user processes. Communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified. Everything at this layer is application-specific. This layer provides application services for file transfers, e-mail, and other network software services. Telnet and FTP are applications that exist entirely in the application level. Tiered application architectures are part of this layer. \n\nPresentation(Layer 6) \nThis layer provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer. \n\nSession(Layer 5) This layer establishes, manages and terminates connections between applications. The session layer sets up, coordinates, and terminates conversations, exchanges, and dialogues between the applications at each end. It deals with session and connection coordination. \nTransport(Layer 4)\n This layer provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control. It ensures complete data transfer. \nNetwork(Layer 3)\n This layer provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node. Routing and forwarding are functions of this layer, as well as addressing, internetworking, error handling, congestion control and packet sequencing. \nData Link(Layer 2) \nAt this layer, data packets are encoded and decoded into bits. It furnishes transmission protocol knowledge and management and handles errors in the physical layer, flow control and frame synchronization. The data link layer is divided into two sublayers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. The MAC sublayer controls how a computer on the network gains access to the data and permission to transmit it. The LLC layer controls frame synchronization, flow control and error checking. \nPhysical(Layer 1)\n This layer conveys the bit stream - electrical impulse, light or radio signal -- through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects. Fast Ethernet, RS232, and ATM are protocols with physical layer components.
141068
There are a few things that are better. For instance OWA is much better in 2003 then it is in 2000. Windows 2003 comes with remote server and desktop capabilities built in and is easier to set up then 2000 terminal server. I don't like that I have to explain why I am shutting down the system everytime I need to reboot.
38849
I assume you mean the OSI Seven-Layer Model.  The Levels are from top to bottom:\n\n(Taken from Connected: An Internet Encyclopedia)\n\n1. The Physical Layer describes the physical properties of the various communications media, as well as the electrical properties and interpretation of the exchanged signals. Ex: this layer defines the size of Ethernet coaxial cable, the type of BNC connector used, and the termination method.\n\n2. The Data Link Layer describes the logical organization of data bits transmitted on a particular medium. Ex: this layer defines the framing, addressing and checksumming of Ethernet packets.\n\n3. The Network Layer describes how a series of exchanges over various data links can deliver data between any two nodes in a network. Ex: this layer defines the addressing and routing structure of the Internet.\n\n4. The Transport Layer describes the quality and nature of the data delivery. Ex: this layer defines if and how retransmissions will be used to ensure data delivery.\n\n5. The Session Layer describes the organization of data sequences larger than the packets handled by lower layers. Ex: this layer describes how request and reply packets are paired in a remote procedure call.\n\n6. The Presentation Layer describes the syntax of data being transferred. Ex: this layer describes how floating point numbers can be exchanged between hosts with different math formats.\n\n7. The Application Layer describes how real work actually gets done. Ex: this layer would implement file system operations.\n\nMore here, http://www.freesoft.org/CIE/Topics/15.htm
129722
US Robotics 56k v.Everything modems worked just fine with Windows 3.1, however, you would want to make sure that your I/O card (which most of them had even back in the early 90's) had a 16550 UART.  This was basically an IO chip which had a 16-byte buffer for faster asynchronous serial transmission.\n\nAlso, in order to use the faster speed more reliably, there were configuration settings that you will want to add to the [386Enh] section of the system.ini configuration file:\n\nCom*FIFO=1\nCom*Buffer=1024 \nCom*TXSize=16 \nCom*RXSize=8\n\n(Where * is the number for your serial port, such as '1' for COM1, etc.)\n\nThis will ensure that the buffer on the 16550 UART is enabled and you have a decent size buffer to achieve higher speeds.  Some people have experienced 150k+ speeds with the proper configuration without buffer overruns or CRC errors.