Planning a QFX3000-M QFabric System Deployment

A QFX3000-M QFabric system is formed by interconnecting QFX3500, QFX3600, or QFX5100 Node devices, QFX3600-I or QFX5100-24Q Interconnect devices, and QFX3100 Director devices. Two Juniper Networks EX Series switches are used to interconnect the control plane and management network.

Before installing a QFX3000-M QFabric system, you must consider the following factors:

• The number of devices in the QFabric system and their location.

  • You must have two QFX3100 Director devices operating in a Director group.

  • You can have up to four Interconnect devices, either QFX5100-24Q or QF3600-I, but not intermixed in the same QFabric Node group.

  • You can interconnect up to 16 QFX Series Switches as Node devices using either QFX5100-24Q or QFX3600-I as the Interconnect Devices. You may not mix QFX5100-24Q Interconnect devices with QFX3600-I Interconnect devices on the same QFX3000-M QFabric system. Supported models are:

    • QFX5100-24Q

    • QFX5100-48S

    • QFX5100-48T

    • QFX3600

    • QFX3500

  • The number of Node devices you require depends on the following factors:

    • 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 1 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 1: Number of 10-Gigabit Ethernet Access Ports Supported on Node Devices Based on Oversubscription Ratio

    Oversubscription Ratio on Access Ports	Number of 10-Gigabit Ethernet Access Ports Supported on a QFX3500 Node Device	Number of 10-Gigabit Ethernet Access Ports Supported on a QFX3600 Node Device	Number of 10-Gigabit Ethernet Access Ports Supported on a QFX5100-24Q Node Device	Number of 10-Gigabit Ethernet Access Ports Supported on a QFX5100-48S and QFX5100-48T Node Device
    1:1 (no oversubscription)	1:1 oversubscription not supported	32	104	1:1 oversubscription not supported
    3:1	48	48	104 ports with 2 QFX-EM-4Q expansion modules	3:1 oversubscription not supported
    3.5:1	3.5:1 oversubscription not supported	3.5:1 oversubscription not supported	3.5:1 oversubscription not supported	56
    6:1	48	48	96 ports with 2 QFX-EM-4Q expansion modules	3:1 oversubscription not supported

    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 2 to determine the number of Interconnect devices you require. For example, if you plan to install 14 Node devices and require 3:1 oversubscription ratio on the Node devices, you must install 4 Interconnect devices.

    Table 2: Maximum Number of Node Devices Supported Based on Oversubscription Ratio and Number of Interconnect Devices

    Oversubscription Ratio	QFX Series Switch Models	Number of Interconnect Devices	Maximum Number of Node Devices
    1:1	QFX3600 or	2	4
    		4	8
    	QFX5100-24Q	8	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices
    2:1	QFX5100-24Q	4	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices
    3:1	QFX3600 QFX3500	2	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices
    		4	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices
    3.5:1	QFX5100-48S or QFX5100-48T	2	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices
    		4	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices
    6:1	QFX5100-24Q QFX5100-48S QFX5100-48T QFX3600 QFX3500	2	32 connecting to QFX5100-24Q Interconnect devices and 16 connecting to QFX3600-I Interconnect devices

  For information about the size and strength of racks for the devices, see the following topics:

  • Rack Requirements for a QFX3100 Director Device

  • Rack Requirements for a QFX5100 Device

  • Rack Requirements for a QFX3600 or QFX3600-I Device

  • Rack Requirements for a QFX3500 Device

  • Rack Requirements for EX4200 Switches

  For the dimensions and weights of the devices, see the following topics:

  • Chassis Physical Specifications for a QFX3100 Director Device

  • Chassis Physical Specifications for a QFX5100 Device

  • Chassis Physical Specifications for QFX3600 and QFX3600-I Devices

  • Chassis Physical Specifications for a QFX3500 Chassis

  • Chassis Physical Specifications for EX4200 Switches

• The type of control plane and management network—copper-based or fiber-based.

  • For a copper-based control plane and management network, use:

    • QFX3100 Director devices with RJ-45 network modules installed

    • QFX5100 Node devices using the RJ-45 network port (C0 and a 1 Gbps SFP installed in network port (C1).

    • QFX3500 Node devices with a 1000BASE-T management board installed

    • EX4200-24T switches with an SFP+ uplink module installed

  • For a fiber-based control plane and management network, use:

    • QFX3100 Director devices with SFP network modules installed

    • QFX5100 Node devices using 1 Gbps SFP installed in network ports (C0) and (C1).

    • QFX3500 Node devices with an SFP management board installed

    • EX4200-24F switches with an SFP+ uplink module installed

• Cabling requirements for the control plane and management network

  • The copper-based control plane and management network are interconnected using standard 1000BASE-T Ethernet over copper wiring. Each network segment can be a maximum length of 100 m (328 ft). See Cable Specifications for Copper-Based Control Plane Connections for the QFabric System.

  • The fiber-based control plane and management network are interconnected using small form-factor pluggable (SFP) transceivers over fiber-optic cabling. Each network segment can be a maximum length of 10 km (6.2 miles). However, keep in mind that each network segment in the data plane is limited to a maximum length of 150 m (492 ft). See The Hardware Compatibility Tool.

• Cabling requirements for the data plane—The data plane is interconnected using standard 40GBASE-SR 40-Gigabit Ethernet QSFP+ optical transceivers over fiber-optic wiring. If you use OM3 optical fiber, each network segment can be a maximum of 100 m (328 ft). If you use OM4 optical fiber, each network segment can be a maximum of 150 m (492 ft). However, keep in mind that if you are using a copper-based control plane and management network, each copper network segment is limited to a maximum length of 100 m (328 ft). This limitation of the copper control plane network segment effectively limits the network segments in your data plane to 100 m (328 ft).See The Hardware Compatibility Tool.

  The data plane cabling requirements depend on the number of connections required from each Node device to Interconnect devices based on the oversubscription ratio you need on the access ports of the Node device. Table 3 shows the number of connections required from each Node device to Interconnect devices based on the oversubscription ratio you need on the Node device.

  Table 3: Number of Connections Required Between Node and Interconnect Devices Based on Oversubscription Ratio

  Oversubscription Ratio	QFX Series Switch Model	Number of Connections from Each Node Device to Interconnect Devices
  1:1	QFX3600 QFX5100-24Q	8
  3:1	QFX3600 QFX3500	4
  3.5:1	QFX5100-48S QFX5100-48T	4
  6:1	QFX5100-24Q QFX5100-48S QFX5100-48T QFX3600 QFX3500	2

• Power supply—You must plan the installation site to meet the power requirements of all the devices in the QFabric system. For information on power requirements and configuration options for each device, see the following topics:

  • AC Power Specifications for a QFX3100 Director Device

  • AC Power Specifications for a QFX3600 or QFX3600-I Device

  • DC Power Specifications for a QFX3600 or QFX3600-I Device

  • AC Power Specifications for a QFX5100 Device

  • DC Power Specifications for a QFX5100 Device

  • AC Power Specifications for a QFX3500 Device

  • DC Power Specifications for a QFX3500 Device

  • Power Specifications for EX4200 Switches

• For more information about the site preparation requirements for each device, see the following topics:

  • Site Preparation Checklist for a QFX3100 Director Device

  • Site Preparation Checklist for a QFX3600 or QFX3600-I Device

  • Site Preparation Checklist for a QFX5100 Device

  • Site Preparation Checklist for a QFX3500 Device

  • Site Preparation Checklist for EX4200 Switches