EX8208 Switch Hardware Overview
Juniper Networks EX8208 Ethernet Switches provide high performance, scalable connectivity, and carrier-class reliability for high-density environments such as campus-aggregation and data-center networks. The EX8208 switch is a modular system that provides high availability and redundancy for all major hardware components, including Routing Engines, switch fabric, fan tray, and power supplies.
You can manage EX8208 switches using the same interfaces that you use for managing other devices running the Juniper Networks Junos operating system (Junos OS)—the command-line interface (CLI), the J-Web graphical interface, and the Network and Security Manager (NSM).
Software
The Juniper Networks EX Series Ethernet Switches 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 EX Series switches also runs on all Juniper Networks J Series, M Series, MX Series, and T Series routers.
Chassis Physical Specifications
The EX8208 switch is 14 rack units (14 U) in size (1/3 rack); three EX8208 switches can fit in a standard 42 U rack. Each EX8208 switch is designed to optimize rack space and cabling. See Figure 1.
Figure 1: EX8208 Switch
The EX8208 switch has a chassis-level LCD panel that displays Routing Engine and switch fabric status as well as chassis components’ alarm information for rapid problem identification. The LCD panel provides a user-friendly interface for performing initial switch configuration, rolling back a configuration, or restoring the switch to its default settings. See LCD Panel in an EX8200 Switch.
The EX8208 chassis backplane distributes the data, control, and management signals to various system components along with distributing power throughout the system.
See Chassis Physical Specifications of an EX8208 Switch.
Routing Engines and Switch Fabric
Switching functionality, system management, and system control functions of an EX8208 switch are performed by a Switch Fabric and Routing Engine (SRE) module. See Switch Fabric and Routing Engine (SRE) Module in an EX8208 Switch. An SRE module contains a Routing Engine and switch fabric. The SRE modules are installed in the front of the chassis in the slots labeled SRE0 and SRE1. See Slot Numbering for an EX8208 Switch. A base configuration EX8208 switch has one SRE module. A redundant configuration EX8208 switch has a second SRE module. See EX8208 Switch Configurations.
The Switch Fabric (SF) module, working with the SRE module, provides the necessary switching functionality to a base configuration EX8208 switch. The SF module is installed in the front of the chassis in the slot labeled SF. In a redundant configuration the SF module provides a redundant switch fabric. The additional switch fabric provides full 2+1 switch fabric redundancy to the switch. See Switch Fabric (SF) Module in an EX8208 Switch.
Line Cards
The EX8208 switch features eight horizontal line card slots and supports the line rate for each line card. The line cards in EX8200 switches combine a Packet Forwarding Engine and Ethernet interfaces on a single assembly. Line cards are field-replaceable units (FRUs) that can be installed in the line card slots labeled 0 through 7 on the front of the switch chassis. See Slot Numbering for an EX8208 Switch. All line cards are hot-removable and hot-insertable.
The following line cards are available for EX8208 switches:
- 8-port 10-Gigabit Ethernet SFP+ line card: This line card has eight 10-gigabit SFP+ ports on its faceplate in which you can install SFP+ transceivers. See 8-port SFP+ Line Card in an EX8200 Switch.
- 40-port 10-Gigabit Ethernet SFP+ line card: This line card has 40 10-gigabit SFP+ ports on its faceplate in which you can install either SFP+ or SFP transceivers. See 40-port SFP+ Line Card in an EX8200 Switch.
- 48-port 100/1000 SFP line card: This line card has 48 1-gigabit SFP ports on its faceplate in which you can install SFP transceivers. See 48-port SFP Line Card in an EX8200 Switch.
- 48-port 10/100/1000 RJ-45 line card: This line card had 48 10/100/1000 Gigabit Ethernet ports with RJ-45 connectors on its faceplate. See 48-port RJ-45 Line Card in an EX8200 Switch.
Cooling System
The cooling system in an EX8208 switch consists of a hot-removable and hot-insertable fan tray. The fan tray contains 12 fans. The fan tray installs vertically on the left front of the chassis and provides side-to-side chassis cooling. See Cooling System and Airflow in an EX8208 Switch.
Power Supplies
Power supplies for the EX8208 switch are fully redundant, load-sharing, and hot-removable and hot-insertable field-replaceable units (FRUs). Each EX8208 switch chassis can hold up to six 2000 W AC, six 3000 W AC, or six 2000 W DC power supplies.
The 2000 W AC power supplies support both low-voltage line (100–120 VAC) and high-voltage line (200–240 VAC) AC power configurations on an EX8208 switch. Each 2000 W AC power supply delivers 2000 W of power at high-voltage line (200–240 VAC) or 1200 W at low-voltage line (100–120 VAC) to the EX8208 chassis.
Each 3000 W AC power supply delivers 3000 W of power at high-voltage line (200–240 VAC) input to the EX8208 chassis. Low-voltage line input is not supported for the 3000 W AC power supplies on the EX8208 switch.
Each DC power supply delivers 2000 W of power to the chassis when the input voltage is in the range –40 VDC through –72 VDC.
Only two AC power supplies are required for the base AC configuration and switch powerup. The redundant AC configuration ships with six AC power supplies to provide the capacity to power the system using N+1 or N+N power redundancy. See AC Power Supply in an EX8200 Switch and EX8208 Switch Configurations.
The redundant DC configuration ships with four DC power supplies. The dual inputs of the DC supplies provide direct support for N+N power redundancy. The redundant configuration also provides sufficient capacity for N+1 redundancy in most configurations; if necessary, up to two additional DC supplies can be added to the system. See DC Power Supply in an EX8200 Switch and EX8208 Switch Configurations.
 | Caution: Mixing different types of power supplies in the same chassis is not supported. |
