Juniper QFX3000-G QFabric, Руководство по развертыванию, Страница: 113 / 652

•
The number of access ports you need for connections to either endpoint systems
(such as servers and storage devices) or external networks.
• The oversubscription ratio you need on the access ports.
•
The number of access ports supported on each Node device based on that
oversubscription ratio.
Table 16 on page 87 shows the number of 10-Gigabit Ethernet access ports supported
on Node devices based on the oversubscription ratio you need on the access ports.
Table 16: Number of 10-Gigabit Ethernet Access Ports Supported on Node Devices Based on
Oversubscription Ratio
Number of 10-Gigabit Ethernet
Access Ports Supported on a
QFX3600 Node Device
Number of 10-Gigabit Ethernet Access Ports
Supported on a QFX3500 Node Device Oversubscription Ratio on
Access Ports
32 1:1 oversubscription not supported on QFX3500
Node devices 1:1 (no oversubscription)
48 48 3:1
48 48 6:1
To calculate the required number of Node devices (N
n
) for your QFabric system,
divide the number of access ports you need for connections to either endpoint
systems or external networks (N
p
) by the number of access ports supported on each
Node device (N
a
) based on the required oversubscription ratio, and round up the
resulting value. For example, if you need 300 10-Gigabit Ethernet access ports at 3:1
oversubscription, and your Node device supports 48 10-Gigabit Ethernet access
ports at 3:1 oversubscription, you require 7 Node devices as shown below:
N
n
= N
p
/N
a
N
n
= 300/48
N
n
= 6.25 (rounded up to 7)
•
The number of Interconnect devices you require depends on the number of Node
devices and the oversubscription ratio required on the access ports of the Node
devices. See
Table 17 on page 87 to determine the number of Interconnect devices
you require. For example, if you plan to install 60 Node devices and require 3:1
oversubscription ratio on the Node devices, you must install 2 Interconnect devices.
Table 17: Maximum Number of Node Devices Supported Based on Oversubscription Ratio and
Number of Interconnect Devices
Maximum Number of Node Devices
Number of QFX3008-I
Interconnect Devices
Oversubscription Ratio
32 2 1:1 (Supported on QFX3600 Node
devices only)
87 Copyright © 2015, Juniper Networks, Inc.
Chapter 6: Before You Begin