Order preserving transmission of data streams
First Claim
1. Method for link switching when transmitting a data stream between two nodes (1 and 2, 11 and 12) of a network such that the order within the data stream is preserved, said two nodes being connected by at least two parallel links (link 1 . . . link n) , of which only one is currently active, the method comprising the steps of:
- a. generating a switch request in the sending node (sender 1,
11);
b. attaching a sequence number to said switch request;
c. transmitting said switch request with its sequence number from the sending node to the receiving node (receiver 2,
12) over at least one currently inactive link,d. determining, in the receiving node (2,
12), whether a received switch request carries a higher sequence number than a switch request received before and is thus acceptable,e. if so, sending to the sending node (1,
11) over said currently inactive link a switch response with the sequence number of said received switch request;
f. determining, in the sending node (1,
11), when receiving a switch response, whether its sequence number matches the sequence number sent with the last switch request and is thus acceptable; and
g. depending on the result of the determining step f, activating an inactive link to transmit the data stream from the sending node to the receiving node.
1 Assignment
0 Petitions
Accused Products
Abstract
Described are methods which preserve the order of the data frames within a data stream if the data stream is switched from one link to another. The first method achieves the order preservation by numbered switch frames that have to be exchanged between the nodes before the link switching is actually performed. In the second method, the switching is only prepared by exchanging special frames which indicate "clean" links. Actual switching takes place by just using an already prepared, i.e., "clean" link.
33 Citations
8 Claims
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1. Method for link switching when transmitting a data stream between two nodes (1 and 2, 11 and 12) of a network such that the order within the data stream is preserved, said two nodes being connected by at least two parallel links (link 1 . . . link n) , of which only one is currently active, the method comprising the steps of:
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a. generating a switch request in the sending node (sender 1,
11);b. attaching a sequence number to said switch request; c. transmitting said switch request with its sequence number from the sending node to the receiving node (receiver 2,
12) over at least one currently inactive link,d. determining, in the receiving node (2,
12), whether a received switch request carries a higher sequence number than a switch request received before and is thus acceptable,e. if so, sending to the sending node (1,
11) over said currently inactive link a switch response with the sequence number of said received switch request;f. determining, in the sending node (1,
11), when receiving a switch response, whether its sequence number matches the sequence number sent with the last switch request and is thus acceptable; andg. depending on the result of the determining step f, activating an inactive link to transmit the data stream from the sending node to the receiving node. - View Dependent Claims (2, 3, 4)
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5. Method for link switching when transmitting a data stream between two nodes (1 and 2, 11 and 12) of a network such that the order within the data stream is preserved, said two nodes being connected by at least two parallel links (link 1 . . . link n), of which only one is currently active, the method comprising the steps of:
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a. generating a sweep request in the sending node (sender 1,
11);b. attaching a sequence number to said sweep request; c. transmitting said sweep request with its sequence number from the sending node to the receiving node (receiver 2,
12) over at least one currently inactive link,d. determining, in the receiving node (2,
12), whether a received sweep request carries a higher sequence number than a sweep request received before and is thus acceptable,e. if so, sending to the sending node (1,
11) over said currently inactive link a sweep response with the sequence number of said received sweep request;f. determining, in the sending node (1,
11), when receiving a sweep response, whether its sequence number matches the sequence number sent with the last sweep request and is thus acceptable; andg. depending on the result of the determining step f, activating an inactive link to transmit the data stream from the sending node to the receiving node. - View Dependent Claims (6, 7, 8)
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Specification