Cabletron Systems 3Com manual Network Control Protocol NCP as described

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Theory of Operation 19

The DB-9,9-pin,RS-232 serial port provides a User Interface (UI) or a Point-to-Point Protocol (PPP) connection. The UI provides basic management tools for the AP. The PPP provides a link between APs using a serial connection. The serial link supports short haul (direct serial) or long haul (telephone line) connections. The AP is a Data Terminal Equipment (DTE) device with male pin connectors for the RS-232 port. Connecting the AP to a PC requires a null-modem cable; connecting the AP to a modem requires a straight-through cable.

Bridging Support The AP PPP interface, accessible from the serial port at the rear of the AP, provides two types of bridging operations: Internet Protocol (IP) bridging between an AP and a computer, and between two APs (with one AP connected to a LAN). To establish an Internet Protocol bridge with an AP, ensure that the computer includes the appropriate Telnet software with PPP and TCP/IP protocols. Using Telnet, a remote computer can connect to any AP on an Ethernet network, as long as data transfers through IP packets.

A PPP link provides the option of using a direct serial link or modem to extend wired Ethernet topologies. Once in PPP mode, the AP automatically attempts to communicate with the other device using the Data-Link Bridging (DLB) protocol. An AP using DLB communicates on the MAC level, and receives and transmits Ethernet frames.

If the other device does not support DLB, the AP attempts to communicate using Internet Protocol Control Protocol (IPCP). An AP using IPCP communicates on the IP level, and receives and transmits IP packets.

The PPP implementation in the AP uses the Link Control Protocol (LCP) and

Network Control Protocol (NCP) as described in:

■RFC 1171: the Point-to-Point Protocol, July 1990.

■RFC 1220: PPP Extensions for Bridging, April 1991.

■RFC 1332: The PPP Internet Protocol Control Protocol, May 1992.

■RFC 1661: The Point-to-Point Protocol, July 1994.

(RFCs are Requests For Comments used in Internet Communities.)

The AP database dynamically tracks wireless clients and APs on the PPP interface. Packets forward to the PPP link after the AP determines their destination.

The PPP implementation in the AP uses the NCP as described in RFC 1220: PPP Extensions for Bridging to encapsulate packets at the Ethernet level. The PPP provides IP bridging control as defined by RFC 1172 and MAC-level bridging. The protocol provides support for PPP negotiations conforming to RFC 1661. Users cannot plug a non-AP node directly into the AP serial port, only AP-to-AP PPP links.

For detailed information, refer to RFC 1171: The Point to Point Protocol and RFC

1220: PPP Extensions for Bridging.

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Contents Version AirConnect 11 Mbps Wireless LAN Access Point User Guide95052-8145 3Com CorporationBayfront Plaza Santa Clara, CaliforniaContents Installing Access Point Hardware Monitoring Wireless Clients Access Point Installation Configuring the AP Access Point Specifications Technical Support Page Topologies Overview of Digital Wireless NetworkingIntroduction AirConnect NetworkOverview of Digital Wireless Networking AirConnect Network Topologies To the Ethernet LAN AirConnect AccessWireless clients PointAirConnect Access Point Results in the original digital data PowerBASE-TWireless clients and APs Radio BasicsRadio Basics 802.1d Spanning Tree Support Wireless LAN Service AreaSite Surveys Filtering and Access Control Network Control Protocol NCP as described PPP Connection Data Rate Requirement Overview of Digital Wireless Networking Theory of Operation Simple Network Management Protocol Snmp Increased MIB Support Using SnmpProgrammable Snmp Trap Support Management protocol MIBMethod Description Using the User InterfaceRequirements Installing Access Point HardwarePrecautions Package ContentsUS line cord Part Number Power OptionsStandard power supply 115/230VAC, 50/60Hz, 24V/14 Remote power distribution system, Part Number AP-PS-11Below Mounting the APWall Mount To mount an AP on a wall Ceiling Mount To mount an AP on a ceiling Mounting the AP PowerBASE-T UsingPowerBASE-T can be used to power the AP Off Blinking Power No power Power on During boot sequence LED IndicatorsCondition, and other activity Electrical Management System EMS operating outlet Troubleshooting3Com Support Center Verify AP OperationNetwork connection verification Verify Network Wiring TopologyPage Forwarding Counts Monitoring StatisticsSystem Properties Interface StatisticsRadio Frequency Ethernet StatisticsStatistics Type Name Definition MiscellaneousStatistics window, select Main Menu→Misc Statistics Press Esc or Previous F4 to exitKnown APs Clearing StatisticsSelect Clear All Statistics Setup Network Web Server Help File Access Gaining Access to the User Interface UI Using a Web BrowserGaining access to the User Interface UI Help File AccessSelect System Configuration Accessing the Web Browser UISelect Virtual Directory Select Close/ExitSelect Save F1 to save the configuration Select Special Functions Select Reset APType the case sensitive AP name Under Configuration, select Security Select System PasswordSelect Easy Setup--Easy Setup Click Add/Delete Gateways Select Easy Setup--Easy SetupParameter Description Adding or Deleting a Range of Allowed Wireless Clients Adding Allowed Wireless ClientsAdding or Deleting Disallowed Wireless Clients Select Configuration--Security For the Short RF Preamble setting, click DisabledConsiderations Enabling or Disabling EncryptionInterface Description Default Condition Enable or disable interfaces on the APFrequency No. of Channels Country Enter the Multicast Mask data and voice values Snmp Trap Description Default Value Select Enabled or Disable All for All Snmp TrapsConfiguring the Originating Modem Filtering to Forward Packets Configuring the Answering ModemFiltering to Discard Packets Under Configuration, select Firmware Removing Filtered Packet Types Networking ProtocolsClick Delete Filter Disabling Type FilteringSpecial Function Description Active. Clear the wireless client association table forWireless Clients Monitoring Wireless ClientsSelect Regular at the Wireless Clients prompt Indicates a 3Com voice-enabled device Latest version. Refer to Manually Updating AP Firmware on Ascii InterfaceVersions Configure the AP for the following Enable serial portArrow/Function Key Control Character Prompt Description To exit from submenus, press EscConfiguring The Serial Port Select Telnet LoginsPress Tab to select System Password To enable and configure the serial port connection on the APSelect Modem Hangup Setting DescriptionConfiguring the Dial-Up System Hanging UpWindow InstallationConfiguring the AP That can associate with this AP. The default is Disabled Wsaid Establishing a Connection PPP DirectPPP with Modems From the answering APs UI Set the Connect Mode to AnswerOriginating AP Answering APFor automatic dial-out, reset the AP Press up/down arrows to toggle between range and individual Range of Wireless ClientsEnable/Disable the ACL Removing Allowed Wireless ClientsRemoving All Allowed Wireless Clients Address Filtering Load ACL from Wireless Client ListAdding Disallowed Wireless Clients Removing Disallowed Wireless ClientsOptions Clearing WirelessSetting Logging Clients from the APAP Firmware Manually UpdatingPrevious version of AP firmware Select Alter Filenames/HELP URL/TFTP and press Enter Remainder of this procedure uses Windows 98 as an exampleType the firmware file name in the Download Filename field Select Transfer from the emulation program menu bar Open the Special Functions windowSelect Send File Select Alter Filenames/HELP URL/TFTP Server and press Enter Download is complete when the UI displaysExtended Roaming Using MD5Authentication Performing PingsEncryption Wireless client and the access pointHex-digit sequence Restoring Configurations Press the Tab key to highlight .Short RF Preamble EnabledSelect Restore Factory Configuration Output Characteristics Access Point SpecificationsPhysical Characteristics Radio Characteristics Frequency No. of Channels CountryNetwork Characteristics World Wide Web Site ServicesTechnical Support Online TechnicalNorth America Latin AmericaTo obtain an RMA number, call or fax Page Ascii IndexSnmp agent 3Com AirConnect Access Point 3Com Corporation Limited WarrantyObtaining Warranty Radio Frequency Interference Requirements Canada Regulatory Compliance Information3Com End User Software License Agreement Important Read Before Using This Product
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