Terminology - Dell Active Fabric Manager Deployment Manual

This section contains the following topics:
•

Terminology

• Gather Useful Information
• Key Core Design Considerations
• Select a Core Design Template
• Type 1: Large Core Design
• Type 2: Medium Core Design
• Type 3: Small Core Design
Terminology
The following terms are unique to the design and deployment of a distributed core:
• Leaf—A switch that connects switch, servers, storage devices, or top-of-rack (TOR) elements.
• Spine—A switch that connects to leaf switches. The spines provides load balancing and redundancy in the
distributed core. There are no uplinks on the spines.
• Edge ports—The uplinks and downlinks on the leaves.
• Uplinks—An edge port link that connects to the WAN, which typically connects to an internet server provider
(ISP).
• Downlinks—An edge port link that connects the leaves to the data access layer. For example, servers or ToR
elements.
NOTE: You must specify an even number of uplinks. The minimum number of uplinks is 2. One uplink is for
redundancy.
• Interconnect links—Links that connect the spines to the leaves. The interconnect link bandwidth is fixed: 40
GbE or 10 GbE.
• Interlink over-subscription ratio—Varies the maximum number of available interconnect links. This ratio
determines the number of interconnect links (the number of communication links between the spine and leaf
devices). The ratio that you specify depends on the bandwidth, throughput, and edge port requirements. The
interlink over-oversubscription ratio does not come off the edge port downlinks.
As you increase the interlink over-subscription ratio:
– The total number of ports for the uplinks and downlinks increase.
– The number of interconnect links from the leaves to the spines decrease.
– The maximum number of available ports increases.
Use the 1:1 interlink over-subscription rate for the non-blocking, line rate between the leaves and spines. Use
this option when you require a lot of bandwidth and not a lot of ports.
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