• _{Communications server is a general label used somewhat loosely in data communications}
  • _{lets define communications server and remote node server}
• _{Communications servers include several CPU boards inside a single enclosure}
  • _{they combine applications server and remote node server functionalities}
• _{Remote node servers are concerned with controlling remote access to LAN-attached reource and acting as a gateway to those resources}
  • _{application services are supplied by the same LAN-attached applications servers that are accessed by locally attached clients}
  • _{three major categories}
    • _{software-only}
      • _{user supplies a powerful server and adds a remote node server software package such as Windows NT RAS}
      • _{a mulitport serial board may be included with the software}
    • _{turnkey solutions}
      • _{fully configured}
      • _{examples are}
        • LANexpress _(Microcom)
        • Remote Lan Node _(Attachmate)
        • LAN Rover _(Shiva)
        • NetBlazer _(Telebit)
        • AccessBuilder 5000 _(3Com)
        • Remote Annex 2000, 4000 _{(Bay Networks)}
    • _{LAN modems}
      • _{a remote node server with one or more integrated modems}
      • _{security and management software are also installed}
  • _{self-contained remote node servers must be compatible with}
    • _{network architecture (ethernet…)}
    • _{network operating system (Novell…)}
    • _{remote client software}
    • _{physical configuration (number of serial ports, port speed)}
    • _{transmission optimization (compression, spoofing)}
    • _{routing functionality (can it route)}
    • _{WAN supported (is it possible to connect to WAN services)}
    • _{Call management}
      • _{dropped calls redialed}
      • _{connect-time limits enforced}
      • _{view status of all remote access calls}
      • _{log reports generated}
      • _{fixed and variable callback supported}
      • _{encryption supported}
  • _{look at fig 6-7}
  • _{note the differentiation lies in relative CPUs and NICs}
  • _{the configurations include (look at figure 6-8 on pages 240 and 241)}
  • _multitasking
  • _{multiple CPUs, 1 NIC}
  • _{multiple CPUs, multiple NICs}
  • _{multiport serial board (does not use system cpu)}
  • _{note comparative features of comm servers on page 242 fig 6-9}