US 5,210,748 A · Address filter unit for carrying out address filter processing among plurality of networks and method thereof

Abstract

The present invention relates to an address filter method and unit to be used in a bridge unit or the like for connecting networks. The address filter unit carries out an address filter processing between a plurality of networks by using address information extracted from an incoming information frame registered in an entry table. In order to improve the processing efficiency of the address filter processing, the address filter unit includes timers corresponding to each address information registration, timer updating means for sequentially and intermittently advancing each timer value, and means for deleting registration of the address information corresponding to the timers from the entry table when a timer value becomes equal to or above a predetermined value. Further, the address filtering method includes a first step for sequentially generating, as an address of the entry table, a function (fi(a), i=1 to n) of a source address extracted from an incoming information frame at the time of a registration in the entry table or a destination address (a) extracted from an incoming information frame at the time of a retrieval from the entry table, a second step for deciding whether or not address information can be registered in an address generated in the first step in the entry table, at the time of registration, and a third step for deciding whether or not address information registered in an address generated in the first step in the entry table is desired address information, at the time of retrieval.

Claims21

Dependent claims

An address filter unit for carrying out an address filter processing between a plurality of networks by using address information extracted from an incoming information frame and registered in an entry table, said address filter unit comprising:

timers corresponding to each registration of address information;
timer updating means for sequentially and intermittently advancing each timer value;
starting means for starting said timer updating means at a predetermined cycle .DELTA.T, wherein said timer updating means intermittently advances each timer value at a time interval .DELTA.t, where .DELTA.t is less than or equal to .DELTA.T divided by a maximum registration number in the entry table;
and means for deleting the registration from said entry table of address information corresponding to said timers when its corresponding timer value becomes equal to or greater than a predetermined value.

1 more element

An address filtering method for carrying out an address filter processing between a plurality of networks by using address information extracted from an incoming information frame registered in an entry table, said address filtering method comprising:

a first step for sequentially generating an address of said entry table as a function (fi(a), i=1 to n) of a source address extracted from an incoming information frame at the time of registration in the entry table or a destination address, where (a) is the source address or the destination address, extracted from an incoming information frame at the time of retrieval from the entry table;
a second step for deciding whether information can be registered in the address generated in the first step in the entry table at the time of registration;
and
a third step for deciding whether address information registered in the address generated in the first step in the entry table is desired information at the time of retrieval wherein the first step, the second step or the third step are pipe-line operated.

1 more element

a first step for sequentially generating an address of said entry table as a function (fi(a), i=1 to n) of a source address extracted from an incoming information frame at the time of registration in the entry table or a destination address, where (a) is the source address or the destination address, extracted from an incoming information frame at the time of retrieval from the entry table;
a second step for deciding whether information can be registered in the address generated in the first step in the entry table at the time of registration;
and
a third step for deciding whether address information registered in the address generated in the first step in the entry table is desired information at the time of retrieval wherein at the time of a retrieval when it has been decided in the third step that the address information registered in the address fi(a) of the entry table is desired information, the retrieval is finished, and
when it has been decided that the address information registered in the address fi(a) of the entry able is not desired information, the retrieval of the address f.sub.i+1 (a) of the entry table generated in the first step is continued.

2 more elements

An address filter unit for carrying out an address filter processing between branch LANs and N trunk networks, where N.gtoreq.1, comprising logical transmission paths or physical transmission paths by retrieving address information extracted from an incoming information frame registered in an entry table, said address filter unit comprising:

priority order decision means for deciding priority order of registration of address information incoming from the branch LANs into the entry table, registration of address information incoming from the N transmission paths of the trunk network into the entry table, and retrieval of address information from the entry table;
and execution means for executing the processing in accordance with the result of a decision.

Dependencies are inferred from the claim text.

Address filter unit for carrying out address filter processing among plurality of networks and method thereof

Life of this patent

Address filter unit for carrying out address filter processing among plurality of networks and method thereof

Life of this patent

Abstract

Claims21