United States Patent   Patent Number: 5,287,530
Davis et al.  Date of Patent: Feb. 15,1994
 MULTICAST SERVER APPARATUS
 Inventors: Simon P. Davis, Romsey; Ian B.
Stewart, North Baddesley, both of
 Assignee: Roke Manor Research Limited,
Romsey, Great Britain
 Appl. No.: 862,662
 Filed: Apr. 2,1992
 Foreign Application Priority Data
Apr. 16, 1991 [GB] United Kingdom 9108088
 Int. CI.'; H04J3/24
 U.S. Q 370/94.1; 370/60
 Field of Search 370/94.1, 60, 108, 60.1,
370/85.15, 58.3, 110.1, 58.1, 58.2
 References Cited
U.S. PATENT DOCUMENTS
5,119,370 6/1992 Terry 370/60.1
5,130,984 7/1992 Cisneros 370/60
5,144,619 9/1992 Munter 370/60.1
FOREIGN PATENT DOCUMENTS
86/02510 4/1986 PCT Int'l Appl. .
8909521 6/1992 PGT Int'l Appl. .
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Using Bus Matrix Switch," IEEE Journal on Selected
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P. Newman et al., "A Slotted Ring Copy Fabric for a
A multicast server apparatus operative to effect the onward transmission of data cells to a plurality of different addresses includes a switch function unit having an input port, an output port and a transfer port, data cells for multicasting being routed from the input port and to the transfer port, first and second header translation units each having an input terminal and an output terminal. The translation units serve respectively as a chainer and as a distributor, the input terminals of the chainer and the distributor being coupled to the transfer port of the switch function unit to receive data for multicasting. The chainer is effective to change address data associated with each data cell fed thereto to a form recognizable by the distributor and to feed back such data cell together with its changed address data to the transfer port. The distributor is effective to convert recognizable address data associated with data cells fed thereto to corresponding route address tags and to feed cells having such address tags to the output port of the switch function unit. Thus, a data cell for multicasting is distributed by the multicasting server apparatus separately to the plurality of different addresses as identified by the address tags.
2 Claims, 3 Drawing Sheets