It260 Essay

491 Words2 Pages
1. What purpose does the OSI stack perform? Is used by equipment vendors, Internet services providers and cable television (catv) service provides when designing and implementing telecommunications networks. 3. What are the advantages of organizing the functions of th OSI module into layers? helps network designer and troubleshooting. 5. What functions resides under the applicaion layer? Resource sharing and device redirection Remote file access Remote printer access Inter-process communication Network management Directory services Electronic messaging (such as mail) Network virtual terminals 7.What functions resides under the transport layer? Message segmentation: accepts a message from the (session) layer above it, splits the message into smaller units (if not already small enough), and passes the smaller units down to the network layer. The transport layer at the destination station reassembles the message. Message acknowledgment: provides reliable end-to-end message delivery with acknowledgments. Message traffic control: tells the transmitting station to "back-off" when no message buffers are available. Session multiplexing: multiplexes several message streams, or sessions onto one logical link and keeps track of which messages belong to which sessions 9. What functions resides under the data link layer? Link establishment and termination: establishes and terminates the logical link between two nodes. Frame traffic control: tells the transmitting node to "back-off" when no frame buffers are available. Frame sequencing: transmits/receives frames sequentially. Frame acknowledgment: provides/expects frame acknowledgments. Detects and recovers from errors that occur in the physical layer by retransmitting non-acknowledged frames and handling duplicate frame receipt. Frame delimiting: creates and recognizes frame boundaries. Frame error checking: checks

More about It260 Essay

Open Document