Relaying apparatus
In a relaying apparatus comprising input side accommodating portions including input side queues, a plurality of output side accommodating portions including output side queues, and a switch fabric for mutually connecting the input side queues and the output side queues in a mesh form, in a time slot of a fixed period, the output side-addressed queue managers corresponding to the output side accommodating portions select a bandwidth guaranteed packet so as to guarantee a bandwidth, and output priority/non-priority signals for indicating which of the bandwidth guaranteed packet and a bandwidth non-guaranteed packet has been selected, and output demand signals of the packet. An inter-output link manager selects the packet having an empty area in the priority queue or non-priority queue of the output side accommodating portion as a destination corresponding to the packet which is demanded to be outputted.
1. A relaying apparatus comprising:
input side accommodating portions including input side queues,
a plurality of output side accommodating portions respectively including output side queues, and
a switch fabric for mutually connecting the input side queues and the output side queues in a mesh form,
each of the input side accommodating portions including;
output side-addressed queue managers provided corresponding to each output side accommodating portion as a destination which select, upon a selection of a bandwidth guaranteed packet or a bandwidth non-guaranteed packet, the bandwidth guaranteed packet so as to guarantee a bandwidth, and which output a priority/non-priority signal for indicating which of the bandwidth guaranteed packet and the bandwidth non-guaranteed packet has been selected, and an output demand signal for demanding an output of the selected packet, and
an inter-output link manager which, in a time slot of a fixed period, selects any of the output side-addressed queue managers in which a corresponding output side accommodating portion as a destination has an empty area in its priority queue when the output demand signal is outputted and the priority/non-priority signal indicates priority, or selects any of the output side-addressed queue managers in which a corresponding output side accommodating portion as a destination has an empty area in its non-priority queue when the output demand signal is outputted and the priority/non-priority signal indicates non-priority, for outputting a packet selected by the output side-addressed queue manager.
2. The relaying apparatus as claimed in claim 1 wherein the time slot is preliminarily allocated to each output side-addressed queue manager, and the inter-output link manager selects the output side-addressed queue manager in a predetermined allocation order when the output demand signal is outputted in each time slot and the priority/non-priority queue corresponding to the priority/non-priority signal has the empty area, and dynamically selects either of the output side-addressed queue managers in a time slot in which no output demand signal is outputted or both of the priority and non-priority queues are full.
3. The relaying apparatus as claimed in claim 2 wherein in empty time slots generated within the fixed period, the inter-output link manager selects any of the output side-addressed queue managers in which a corresponding output side accommodating portion as a destination has an empty area in its non-priority queue from among all of the output side-addressed queue managers which output the output demand signals and in which priority/non-priority signals indicate the non-priority.
4. The relaying apparatus as claimed in claim 1 wherein in each time slot the inter-output link manager preferentially selects any of the output side-addressed queue managers in which a corresponding output side accommodating portion as a destination has an empty area in its priority queue from among the output side-addressed queue managers which output the output demand signals and in which priority/non-priority signals indicate the priority.
5. The relaying apparatus as claimed in claim 4 wherein the inter-output link manager selects a same output side-addressed queue manager a plurality of times within the fixed period.
6. The relaying apparatus as claimed in claim 1 wherein the input side accommodating portion assigns an identifier indicating the priority or non-priority respectively to the bandwidth guaranteed packet or bandwidth non-guaranteed packet, so that the output side accommodating portion recognizes a received packet as either of the bandwidth guaranteed packet or bandwidth non-guaranteed packet based on the identifier.
7. The relaying apparatus as claimed in claim 1 wherein the input side accommodating portions and the output side accommodating portions further manage the bandwidth guaranteed packet divided into a plurality of queues with a priority order.
8. The relaying apparatus as claimed in claim 1 wherein the input side accommodating portions and the output side accommodating portions manage the bandwidth non-guaranteed packet divided into a plurality of queues.
9. The relaying apparatus as claimed in claim 1 wherein the packet comprises an arbitrary length packet, and the output side-addressed queue managers insert one or more arbitrary length packets into the time slot.
10. The relaying apparatus as claimed in claim 9 wherein the time slot is divided into a plurality of sub-time slots, which are inserted with the packets.
11. The relaying apparatus as claimed in claim 1 wherein the priority and non-priority queues can simultaneously store the packets which simultaneously arrive within a same time slot from the input side accommodating portions.
12. The relaying apparatus as claimed in claim 3 wherein in the empty time slots generated within the fixed period, the selection is performed by a round-robin method unrestrained by the fixed period.