DATA COMMUNICATIONS
Prof. Dr. Hermann Gruenwald
____________________________________________________
____________________________________________________
MIS 4223
DATA COMMUNICATIONS
Prof. Dr. Hermann Gruenwald
____________________________________________________
Hermann Gruenwald Review Question Set Two Chapter 5 LAN Is a combination of hardware and software technology that allows computers to share a variety or resources such as: printers and other peripheral devices data application programs storage devices Negative aspects Speed, if network goes down everyone is down, depending on network and resources shared Popular business uses connecting various physical locations in a building, technical accounting 7. Protocol a protocol is a set of rules that govern communication between hardware and or software component What is the overall purpose of the physical layer? Physical layer = layer 1 is responsible for the establishment, maintenance and termination of physical connections between communicating devices. Header and trailer additional information added to the front of data is called a header information added to the back of data is called a trailer 24. Early token release mechanism The token is set to free and released as soon as the transmission of the data frame is completed rather than waiting for the transmitted data frame to return first. Ethernet and Token Ring Ethernet is more affordable and available 10 Mbps with collision 6 Mbps actual throughput token ring each pc is a part of the network, less collisions 3 standard for 100baseT 100BaseTX - 2 pair of Category UTP 100BaseT4-4pair of category 3,4,5 UTP 100BaseFX-fiber optic cable Isochronous ethernet and ISDN iso-ethernet network architecture is close related with ISDN integrated services digital network iso ethernet network is limited to 100m Chapter 6 4.LAN switches stand-alone workgroup/departmental LAN switches backbone-attached workgroup/departmental backbone/data center switches Full-duplex has switch dependent capabilities NIC The network cards are the keeper of the MAC layer 12. Bus-mastering DMA NIC bus transfer techniques: bus-mastering DMA adapter card CPU temporarily stores data in its RAM PCMCIA CSS There is no guarantee that a particular PCMCIA card will work well, if at all with a particular computer. hubs from different vendors local hub management software is usually vendor specific LAN Cut-through switches read only address info in the MAC layer Store-and-forward switches read entire frame into shared memory error-free cut-through switches read both addresses and frame check sequence ATM capabilities switches LAN architecture extremely quickly also quick switching of voice, video and image traffic. most common UTP Unshieldee twisted pair category 1 UTP 22 or 24 AWG category 2 UTP 22 or 24 AWG category 3 UTP 24 AWG category 4 UTP 22 or 24 AWG category 5 UTP 22 or 24 AWG 42. Twisted Pair trickier than UTP improperly installed shielded twisted pair can actually increase interference proper grounding is important. Chapter 7 1. peer-to-peer network operating systems DOS client/server network operating systems NetWare 3.12 3. Client network operating system client/server network operating system 19. PnP components: PCMCIA cards hot docking dynamic reconfiguration-aware application software 20. Windows 95 22. client software and network drivers network transport protocols network redirectors that trap API 24. need for synchronized versions of files on laptops and desktop workstations 26. distributed implies that different portions of the data are physically stored on multiple distributed servers linked via the network replicated implies that multiple copies of identical data may be stored on multiple servers for redundancy and fault tolerance 35. Microsoft SNA The SNA translation becomes a gateway to the SNA network 46. Enterprise network in a client server information systems 48. A enterprise network carries the following traffic Chapter 8 3. lack of interoperatability system to system connection 6. frame relay's assumptions 8. DOV voice and data don't share same destination 11. switching and transmission differences switching avoids direct connections 28. multiple PVCs per access line 34. POTS plain old telephone service ISDN integrated services digital network 43. ADSL asymmetric digital subscriber line 46. cable modems 49. B-ISDN 51. BRI PRI ISDN Chapter 9 1. Internetworking 6. bridge elements 7. routers vs. Bridges 8. data-link layer addresses y routers 9. network layer addresses by routers 11. router services 18. filtering forwarding 25. nonroutable protocol 28. boundary routers dial-up routers 33. routing and switching Chapter 10 1. remote access trends 3. remote node remote control 6. remote access security 8. communication server remote access links 9. communications servers remote node servers remote pc operates as if it is locally 11. dial-out solutions redirect information dial-in solutions LAN modem 15. CSMA/CD CDMA/CA carrier sense multiple access with collision avoidance collisions can not be detected in wireless environments 16. roaming users can move between transmission ranges 28. Oracle Mobile Agents produces mobile ware applications 34. screen catching only change of screens network catching or LAN catching overall remote note performance 41. analog 800 MHZ range digital cellular 140 MHz range challenge maximize simultaneous connections
To hear the announcement
click on the speaker below! 