Technical Documentation
QFX3008-I Interconnect Device Overview
The QFX3008-I Interconnect device is a half-rack, modular, fully redundant chassis that provides the data plane switch fabric for Juniper Networks QFX3500 Node devices. Together the QFX3500 Node device and the QFX3008-I Interconnect device form a multistage, nonblocking switch fabric that provides a high-performance, low-latency, unified interconnect solution for next-generation data centers. See Understanding the QFabric Switch Data Plane.
The QFX3500 Node devices and QFX3008-I Interconnect Devices are connected to Juniper Networks QFX3100 Director devices in an out-of-band management network through Juniper Networks EX4200 Ethernet Switches. The QFX3100 Director devices present the QFabric system devices as a single network entity, which enables simplified management of your data center using the Junos OS command-line interface (CLI) or Junos Space. See Understanding the QFabric Switch Control Plane.
Software
QFX Series devices run under the Juniper Networks Junos OS, which provides Layer 2 and Layer 3 switching, routing, and security services. The same Junos OS code base that runs on QFX Series devices also runs on all Juniper Networks EX Series switches, and J Series, M Series, MX Series, and T Series routers.
Chassis Physical Specifications, Front Panel Display, and Midplane
The QFX3008-I Interconnect device is 21 rack units (21 U) in size (1/2 rack) and designed to fit in industry-standard 19-inch rack-mount enclosures. See Figure 1, Figure 2, and Chassis Physical Specifications for a QFX3008-I Interconnect Device.
Figure 1: QFX3008-I Interconnect Device Front
Figure 2: QFX3008-I Interconnect Device Rear
The QFX3008-I Interconnect device has a front panel display that displays chassis components’ alarm information for rapid problem identification. See Front Panel Display of the QFX3008-I Interconnect Device.
The QFX3008-I Interconnect device midplane distributes the data, control, and management signals to system components and distributes power throughout the system. See Midplane in a QFX3008-I Interconnect Device.
16-Port QSFP+ Front Card
The 16-port quad small form-factor pluggable plus (QSFP+) front cards act as one stage in the multistage switch fabric data plane in the QFX3000 QFabric system. The front cards are hot-insertable and hot-removable field-replaceable units (FRUs). Up to eight front cards are installed in the front of the chassis in the slots labeled 0 through 7. See 16-Port QSFP+ Front Cards in a QFX3008-I Interconnect Device and Understanding the QFabric System Hardware Architecture.
Control Board
The QFX3008-I Interconnect device is connected to the QFabric system control plane through four Gigabit Ethernet small form-factor pluggable plus (SFP+) interfaces on each Control Board. The Control Boards are hot-insertable and hot-removable field-replaceable units (FRUs) that are installed in the rear of the chassis in the slots labeled CB 0 and CB 1. See Control Board in a QFX3008-I Interconnect Device.
Rear Card
The rear cards act as one stage in the multistage switch fabric data plane in the QFabric system. The rear cards are hot-insertable and hot-removable field-replaceable units (FRUs). Eight rear cards are installed in the rear of the chassis in the slots labeled 0 through 7. In a QFX3008-I Interconnect Device, all eight rear cards are active and must be installed in the switch for normal operation. If a single rear card fails, the input/output traffic for that card is load-balanced among the remaining rear cards to provide graceful degradation in switching performance. The impact of a rear card failure on the performance of a QFX3008-I Interconnect device varies based on the number of QFX3500 Node devices installed in the QFabric system and the traffic mix flowing through them. See Rear Cards in a QFX3008-I Interconnect Device and Understanding the QFabric System Hardware Architecture.
Cooling System
The cooling system in a QFX3008-I Interconnect device consists of ten hot-insertable and hot-removable field-replaceable unit (FRU) fan trays: a front fan tray, a rear fan tray, and eight side fan trays. The side fan trays are identical and interchangeable. There are field-replaceable filters on each side fan tray, and below the front fan tray. See Cooling System and Airflow in a QFX3008-I Interconnect Device.
Power Supplies and Wiring Trays
Power supplies for the QFX3008-I Interconnect device are fully redundant, load-sharing, and hot-insertable and hot-removable field-replaceable units (FRUs). Each QFX3008-I Interconnect device holds six power supplies. See AC Power Supply in a QFX3008-I Interconnect Device.
Wiring trays distribute the input power to the power supplies. Wiring trays for the QFX3008-I Interconnect device are fully redundant, hot-insertable and hot-removable field-replaceable units (FRUs). Each QFX3008-I Interconnect device holds two wiring trays. See Wiring Tray in a QFX3008-I Interconnect Device.
 | Caution: Mixing different types of wiring trays in the same chassis is not a supported configuration. |
