Abstract

A method for handling data frames (71,81) by a bridge (51) between a first network (61) which does not require route information within data frames (71,81) and a second network (21,22,23,24,25) requiring route information (74) within data frames (71,81) is presented. A system memory (12) includes an address table (14,140,141). In the address table (14,140,141) are a plurality of entries. Each entry is for a single station (31-60) on the first network (61) or the second network (21,22,23,24,25). Each entry contains a first field (17,170,171) which is the address of the station (31-60) and when the station (31-60) is in the second network (21,22,23,24,25) the entry additionally includes a second field (19,191) which contains a route to the station (31-60). When a first data frame (81) having a first destination address (72) is received from the first network (61), the address table (14,140,141) is checked for an entry which has the first destination address (81) in the first field (17,170,171). If an entry is found indicating that the first destination address (81) is for a station (31-54) in the second network (21,22,23,24,25), the route information (74) in the second field (19,191) is added to the first data frame (81) to create a first modified data frame and the first modified data frame is sent out on the second network (21,22,23,24,25). If no entry is found for the first destination address (81) a route discovery process is initiated to discover a route to the station (31-54) on the second network (21,22,23,24,25) with the first destination address (81).

Other References

• "Draft Addendum to ANSI/IEEE Std 802.5-1988 Token Ring MAC & PHY Specification Enhancement for Multiple-Ring Networks", prepared by the IEEE 802.5 Rapporteur on Multiple-Ring Networks IEEE, Inc., Dec. 9, 1988, pp. 1-2