Method and apparatus for source routing bridging

Claim 2

In a multiple network communication system, a method for determining when to copy frames from a network which are candidates for forwarding through a bridge to another network, comprising the steps of: defining Segment Numbers which comprise a network number and a bridge number; defining at least a Primary Segment Number comprising a primary network number and a bridge number corresponding to each bridge; defining a Routing Information Field for inclusion in each frame comprising a Routing Control Word and at least a Segment Number; unidirectionally scanning each frame, including the substeps of parsing the frame for the Routing Information Field, reading the Routing Control Word from the Routing Information Field, and parsing through the Segment Numbers in the frame in one direction; and deciding on-the-fly whether to copy a scanned frame by an interfacing Protocol Handler for forwarding through a bridge, including the substeps of contemporaneously comparing said Primary Segment Number with each of said Segment Numbers to achieve a predetermined result, and interpreting the resulting independently of previous comparisons as being a copy or no-copy decision using specific information in a look-up table identified by said Routing Control Word.

Claim 3

The method for determining when to copy frames in claim 1 wherein said networks are of the token ring type.

Claim 4

In a multiple network communication system, a method for determining when to copy frames from a network which are candidates for forwarding through a bridge to another network, comprising the steps of: defining Segment Numbers which comprise a network number and a bridge number; defining at least a Primary Segment Number comprising a primary network number and a bridge number corresponding to each bridge; defining at least a Secondary Segment Number comprising an alternate network number and a bridge number corresponding to each bridge; defining a Routing Information Field for inclusion in each frame comprising a Routing Control Word and at least a Segment Number; unidirectionally scanning each frame, including the substeps of parsing the frame for the Routing Information Field, reading the Routing Control Word from the Routing Information Field, and parsing through the Segment Numbers in the frame in one direction; and deciding on-the-fly whether to copy a scanned frame by an interfacing Protocol Handler for forwarding through a bridge, including the substeps of determining from the Routing Control Word whether the Primary Segment Number or the Secondary Segment Number is to be compared with each of the Segment Numbers, contemporaneously comparing said Primary Segment Number or said Secondary Segment Number with each of said Segment Numbers to achieve a predetermined result, and interpreting the result independently of previous comparisons as being a copy or no-copy decision; using specific information in a look-up table identified by said Routing Control Word.

Claim 5

In a multiple network communication system, a method for determining when to copy frames from a network which are candidates for forwarding through a bridge to another network, comprising the steps of: defining Segment Numbers which comprise a network number and a bridge number; defining at least a Primary Segment Number comprising a primary network number and a bridge number corresponding to each bridge; defining at least a Secondary Segment Number comprising an alternate network number and a bridge number corresponding to each bridge; defining a Routing Information Field for inclusion in each frame comprising a Routing Control Word and at least a Segment Number; unidirectionally scanning each frame, including the substeps of parsing the frame for the Routing Information Field, reading the Routing Control Word from the Routing Information Field, and parsing through the Segment Numbers in the frame in one direction; and deciding on-the-fly whether to copy a scanned frame by an interfacing Protocol Handler for forwarding through a bridge, including the substeps of determining from the Routing Control Word whether the Primary Segment Number or the Secondary Segment Number is to be compared with each of the Segment Numbers, contemporaneously comparing said Primary Segment Number or said Secondary Segment Number with each of said Segment Numbers to achieve a predetermined result, and interpreting the result independently of previous comparisons as being a copy or no-copy decision; using specific information in a look-up table identified by said Routing Control Word.

Claim 6

The method for determining when to copy frames in claim 3 wherein said networks are of the token ring type.

Claim 7

A multiple network communication system comprising: a bridge, coupled between first and second networks, which forwards frames of data from one network to the other; and a device connected between the bridge and said first network, wherein said device: scans each frame of data while each frame of data is on the first network; parses each frame for a Routing Information Field; reads a Routing Control Word from the Routing Information Field; parses through Segment Numbers in the frame in one direction; `identifies on-the-fly frames of data destined for the second network; and controls the forwarding of identified frames of data from the first network to the bridge; said device includes: a. logic circuitry which contemporaneously compares a Primary Segment Number with each of said Segment Numbers to achieve a predetermined result, and interprets the result independently of previous comparisons as being a copy or no-copy decision; b. look-up tables used by said logic circuitry to determine whether the decision is a copy or no-cop decision; and c. a state machine which receives the copy decisions from the logic circuitry and provides signals to control the forwarding of identified frames of data.

Claim 8

A multiple network communication system comprising: a bridge, coupled between first and second networks, which forwards frames of data from one network to the other; and a device connected between the bridge and said first network, wherein said device: scans each frame of data while each frame of data is on the first network; parses each frame for a Routing Information Field; reads a Routing Control Word from the Routing Information Field; parses through Segment Numbers in the frame in one direction; `identifies on-the-fly frames of data destined for the second network; and controls the forwarding of identified frames of data from the first network to the bridge; said device includes: a. logic circuitry which contemporaneously compares a Primary Segment Number with each of said Segment Numbers to achieve a predetermined result, and interprets the result independently of previous comparisons as being a copy or no-copy decision; b. look-up tables used by said logic circuitry to determine whether the decision is a copy or no-cop decision; and c. a state machine which receives the copy decisions from the logic circuitry and provides signals to control the forwarding of identified frames of data.