BCM567X BOARDCOM [Broadcom Corporation.], BCM567X Datasheet - Page 10

• Manufacturer Part Number: BCM567X
• Description: A Scalable Approach to Gigabit Ethernet Switch Design
• Manufacturer: BOARDCOM [Broadcom Corporation.]

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The two primary chip components of the Broadcom StrataXGS Gigabit Ethernet switch architecture are the StrataXGS
BCM5670 and the StrataXGS BCM5690. The BCM5670 is a high-speed (160-Gbps) switch fabric, also called a backplane
or interconnect, that has eight 10-Gbps ports. A smaller version, the BCM5671, is an 80-Gbps switch fabric with four
10-Gbps ports. The 10-Gbps ports on the BCM5670 and BCM5671 are the building blocks for interconnecting line cards to
a switch fabric. A 10-slot chassis, for example, can be designed with eight line cards and two management cards.
The 10-Gbps ports on the BCM5670/71 accept traffic from the 10-Gbps uplinks in other chip components, these can be
arranged in a variety of configurations to build a Gigabit Ethernet switch of the size and configuration that matches the
designer’s business plan. Once traffic is placed on the switch fabric, it is switched, with no delay, to its egress port.
Switching with no delay is possible because the total bandwidth available on the switch fabric is greater than the sum of the
speeds of all the ports feeding traffic onto it. Therefore, no buffering queues are required that could introduce added delays.
This design approach is called a nonblocking architecture. Combining chips expands the number of ports in a system while
also retaining the nonblocking throughput characteristics of a single switch.
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TRATA
BCM567x/BCM569x
4
StrataXGS Product Family
XGS P
Frame tag
Lookup of
RODUCT
HiGig
F
AMILY
HiGig
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Figure 1: BCM5670 Block Diagram
QUEUE SYSTEM
10G
10G
Bro adco m C orp or atio n
RAM
RAM
ARL
HiGig
HiGig
10G
10G
10G
On-chip Memory
8 priority levels
per port
Document
567x_569x-WP100-R
White Paper
06/27/02