BROADCAST/MULTICAST FILTERING BY THE BRIDGE-BASED ACCESS POINT

    公开(公告)号:CA2137587C

    公开(公告)日:1999-03-23

    申请号:CA2137587

    申请日:1994-12-08

    Applicant: IBM CANADA IBM

    Abstract: In communication systems which include high speed wired local area networks (LAN s) and low speed wireless LANs, the bandwidth of the wireless LANs can be severely impa cted. It has been found that many broadcast or multicast messages which are forwarded to the wireless LANs are not required as the mobile terminals which would receive the m essages are not required to act on them. The present invention provides a means and meth od to filter out unneeded messages so that they do not impact the bandwidth of the wir eless network. Each access point for each wireless LAN maintains a table of parameters for each associated mobile terminal in the connected wireless LAN. The parameters in that table are compared to the parameters in message frames received by the access point an d only those messages having parameters found in the table are put on the wireless LAN. The level of filtering can be controlled by specifying which parameters are to be us ed for filtering messages. The tables at each access point are maintained current by mo ving table entries from access point to access point as mobile terminals move from wireless LAN to wireless LAN and by removing inactive table entries from the table when a predet ermined interval of inactivity is encountered and a terminal is determined to be no long er in active contact with the access point.

    METHOD AND DEVICE FOR SECURING THREE-WAY CONNECTION AMONG MOBILE CALCULATION DEVICE, FIXED CALCULATION DEVICE AND COMPUTER NETWORK

    公开(公告)号:JPH10117208A

    公开(公告)日:1998-05-06

    申请号:JP15346497

    申请日:1997-06-11

    Applicant: IBM

    Abstract: PROBLEM TO BE SOLVED: To switch a pass-through mode to a bridge mode in response to the connection secured to a mobile calculation device by peparing a packet path designation means, in addition to a means which redirects an information packet between a computer network and a fixed calculation device. SOLUTION: A mobile calculation device 14 (for example, notebook type personal computer(PC)) is connected to a fixed calculation device 12 (desktop- type PC) via a radio communication channel (infrared link) 16. Under such conditions, a system operates in a bridge mode and mutually redirects an information packet between the PC 14 and an Ethernet LAN 10 via the PC 12. When no PC 14 is connected to the system, the system operates in a pass- through mode and filters all non-broadcast communication message traffics received from the LAN 10 by an Ethernet adaptor, based on the network address of the PC 12 or a group address.

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