PM8611-BIAP PMC [PMC-Sierra, Inc], PM8611-BIAP Datasheet - Page 265

• Manufacturer Part Number: PM8611-BIAP
• Manufacturer: PMC [PMC-Sierra, Inc]

13.3.3
13.3.4
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2010883, Issue 2
Bi-partite graphs
A general solution to the connection problem is a schedule where each connection is assigned to
one of the 9720 timeslots in each time stage such that no two connections conflict. This solution
then maps to physical switch settings for the SBSLITE and NSE-20G devices. The following
definitions allow us to represent the problem as an abstract graph problem:
1. Draw a graph where each input and output port is represented as a node.
2. Partition the graph so that all of the input ports are in one partition and all the output ports
3. Draw an edge from an input node to an output node if there is a connection from the
This results in a bipartite graph where each node has a maximum degree of 9720 (the total
number of possible connections from/to a port). A subset of this problem (6 nodes, 2 timeslots) is
illustrated in Figure 23. We want to assign the edges (connections) to timeslots such that no
coincident edges are assigned to the same timeslot. Notice that a solution to the problem consists
of a permutation (or partial permutation) mapping of input nodes onto output nodes for each of
the timeslots. These permutation mappings correspond to one set of switch settings for the NSE-
20G devices.
Figure 25 Example Graph
Unicast
Scheduling unicast connections through the NSE-20G is a relatively simple problem: given n
input ports, n output ports, m time slots and a guarantee that no port is oversubscribed, schedule
the transfer of all input slots to output slots. This solution uses the time slot interchange on the
SBSLITE chips to schedule the flow of inputs to outputs through the NSE-20G fabric with no
collisions.
Unicast connections have a perfect solution.
are in the other.
corresponding input port to the corresponding output port.
A
1
B
2
C
3
Outputs
Inputs
D
4
E
5
SBSLITE™ Telecom Standard Product Data Sheet
F
6
Preliminary
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