# Overview

Slots for line modules, switch route processor (SRP) modules, and switch fabric module (SFM) modules are located in the front of the router, while slots for input/output adapters (IOAs) and SRP IOAs are located in the rear.

- In the E320 Broadband Services Router, modules mount vertically in a 15–slot chassis, numbered left to right (0–16). See Figure 12 and Figure 13 for front and rear views of the router.

  Figure 12: E320 Router, Front View

  Figure 13: E320 Router, Rear View

- In the E120 Broadband Services Router, modules mount horizontally in a 9–slot chassis, numbered bottom to top (0–10). See Figure 14 and Figure 15 for front and rear views of the router.

  Figure 14: E120 Router, Front View

  Figure 15: E120 Router, Rear View

For details about available line modules, IOAs, and compatibility between line modules and SRP modules, see the E120 and E320 Module Guide.

## Slot Numbering

Slot numbering for the routers is similar.

- In the E320 router, modules mount vertically in a 15–slot chassis, numbered left to right (0–16). See Figure 16 and Table 3 for slot locations. Because two half-height IOAs can be installed in a slot, the upper bay is designated Adapter 0 and the lower bay is designated Adapter 1. The router does not have slot groups.

  Figure 16: E320 Slot Numbering

- In the E120 router, modules mount horizontally in a 9–slot chassis, numbered bottom to top (0–10). See Figure 17 and Table 3 for slot locations. Because two half-height IOAs can be installed in a slot, the right bay is designated Adapter 0 and the left bay is designated Adapter 1. The router does not have slot groups.

  Figure 17: E120 Slot Numbering

Table 3: Module Slot Locations

Component | Chassis Location | Slot
--- | --- | ---
LM (line module) | Front | E320 router—0–5, 11–16 E120 router—0–5
SRP module | Front | 6, 7
Blank filler panel | Front | Non-numbered empty slot between 6 and 7
SFM module | Front | 8, 9, 10
IOA | Rear | E320 router—0–5, 11–16 Upper bay: Adapter 0 Lower bay: Adapter 1 E120 router—0–5 Right bay: Adapter 0 Left bay: Adapter 1

## IOA Slot Combinations

Depending on the software release and IOA type, you must install IOAs in certain slots and bays combined with other IOAs in the same slot:

- You must insert some IOAs only in the upper bay or right bay (Adapter 0) of each IOA module slot. If you insert one of these IOAs into a lower bay or left bay (Adapter 1) slot, the line module diagnostics fail, an error message states that the bottom slot is not supported for the currently installed software release, and the slot is disabled.
- If you insert an unrecognized IOA, such as an IOA that is not supported by a particular software release, the line module diagnostics fail, an error is generated, and the slot is disabled.
- If you remove an IOA and replace it with a different IOA in the same slot, an error message states the mismatch and the slot is disabled.
- Full-height IOAs take up the entire slot (both Adapter 0 and Adapter 1).

For information about working with modules and IOAs, see JunosE System Basics Configuration Guide, Chapter 6, Managing Modules. See Table 4 for currently available IOAs and the bays in which you may insert them.

Table 4: IOA Locations and Combinations

IOA | Upper/Right Bay (Adapter 0) | Lower/Left Bay (Adapter 1) | Both Bays Concurrently | Combined with Other IOAs in Same Slot | Hot-Swapping Support
--- | --- | --- | --- | --- | ---
ES2-S1 GE-4 | Yes | Yes | No | No | Yes
ES2-S1 GE-8 | Yes | Yes | Yes | Yes (GE-8 when paired with ES2 4G LM or ES2 10G LM; GE-8, OC3/STM1, and OC12/STM4 IOAs when paired with ES2 4G LM) | Yes
ES2-S3 GE-20 | Yes (Full-height IOA) | Not applicable | Not applicable | Not applicable | No
ES2-S1 10GE | Yes (Full-height IOA) | Not applicable | Not applicable | Not applicable | No
ES2-S2 10GE PR | Yes (Full-height IOA) | Not applicable | Not applicable | Not applicable | No
ES2-S1 OC3-8 STM1 ATM | Yes | Yes | Yes | Yes (GE-8, OC3/STM1, and OC12/STM4 IOAs only) | Yes
ES2-S1 OC12-2 STM4 ATM | Yes | Yes | Yes | Yes (GE-8, OC3/STM1, and OC12/STM4 IOAs only) | Yes
ES2-S1 OC12-2 STM4 POS | Yes | Yes | Yes | Yes (GE-8, OC3/STM1, and OC12/STM4 IOAs only) | Yes
ES2-S1 OC48 STM16 POS | Yes | Yes | No | No | Yes
ES2-S1 SERVICE | Yes (Full-height IOA) | Not applicable | Not applicable | Not applicable | No
ES2-S1 REDUND | Yes (Full-height IOA; slots 0 and 11 only) | Not applicable | Not applicable | Not applicable | No

## Module Combinations

Line modules can only be paired with specific IOA, SFM, and SRP modules. See Table 5 for valid combinations.

Table 5: Module Combinations

Modules | ES2 4G LM | ES2 10G UPLINK LM | ES2 10G LM | ES2 10G ADV LM
--- | --- | --- | --- | ---
SRP Modules |  |  |  |
SRP-100 This module is only supported in the E320 router. | √ | √ | √ | –
SRP-120 This module is only supported in the E120 router. | √ | √ | √ | √
SRP-320 | √ | √ | √ | √
SFM Modules |  |  |  |
SFM-100 This module is only supported in the E320 router. | √ | √ | √ | –
SFM-120 This module is only supported in the E120 router. | √ | √ | √ | √
SFM-320 | √ | √ | √ | √
IOA Modules |  |  |  |
ES2-S1 GE-4 | √ | – | – | –
ES2-S1 GE-8 | √ | – | √ | √
ES2-S3 GE-20 | – | – | √ | √
ES2-S1 10GE | √ | – | – | –
ES2-S2 10GE PR | – | √ | √ | √
ES2-S1 OC3-8 STM1 ATM | √ | – | – | –
ES2-S1 OC12-2 STM4 ATM | √ | – | – | –
ES2-S1 OC12-2 STM4 POS | √ | – | – | –
ES2-S1 OC48 STM16 POS | √ | – | – | –
ES2-S1 REDUND | √ | √ | √ | √
ES2-S1 SERVICE | √ | – | – | –

## IOAs Requiring SFPs

Small form-factor pluggable transceivers (SFPs) are used on most IOAs. A range of SFPs that support different optical modes (multimode and single mode) and cabling distances are available. You can replace SFPs without disabling the interface or removing the module from the system. See Installing and Removing SFPs for more information and the E120 and E320 Module Guide for IOAs that use SFPs.

| Note: Because SFPs are the same shape and size, you are able to insert an SFP that is not compatible with the IOA. Be sure the SFP you are installing is appropriate for the interface you are plugging it into. If you insert the wrong SFP, software diagnostics detect the error.

## Proper Handling of ES2 4G LMs

Use extra caution when handling an ES2 4G LM so that you do not damage module components or dislodge the heat sinks.

| Note: When lifting, carrying, or holding the module, do not grasp it near the six heat sinks along the top and bottom edge of the module. Instead, hold the module along the faceplate and the edges, keeping your fingers and thumbs away from all components. Do not use either row of heat sinks as a handle when carrying the module. You might dislodge or damage them.

Figure 18: LM4 Heat Sink Locations

## ES2 10G Uplink Line Modules

In a 100 Gbps fabric configuration, you must install the ES2 10G Uplink line module in slot 2 or slot 4 only.

- If you install the line module in a slot other than slot 2 or slot 4, it will be disabled.
- If you install the module next to a configured line module that is already installed in slot 3 or slot 5, the ES2 10G Uplink line module will be disabled.

Conversely, if you install a line module in slot 3 or slot 5 next to a previously installed ES2 10G Uplink module, the non-ES2 10G Uplink module will be disabled. For example, if you install an ES2 10G Uplink line module in both slot 2 and slot 4 in an E320 router, you can install the ES2 4G line module in the following locations: 0-1 and 6-11.

## Managing Modules Using the Software

For information about software procedures associated with replacing and managing modules and IOAs, see JunosE System Basics Configuration Guide, Chapter 6, Managing Modules.

## Order of Installation

Before you attempt to install or replace a line module (inserted in the front of the chassis), make sure a compatible IOA (inserted in the rear of the chassis) is already in place. The slot diagnostics run when a line module is installed in a chassis slot. If a compatible IOA module is not present, the diagnostics fail, and you need to remove and reinsert the line module.

## Hot-Swapping Modules

The router supports hot-swapping of line modules and IOAs. Hot-swapping enables you to add or remove a line module without powering down the system. IOAs that support hot-swapping enable you to add or remove an IOA without rebooting the line module. See Table 4 for a list of hot-swappable IOAs.

## Protecting Modules and Slots

The E320 router has two ESD (electrostatic discharge) grounding jacks. The front jack is located below the air filter bezel in the center of the router. The rear jack is located in the upper-right corner of the chassis. The E120 router has one ESD grounding jack located in the upper-right corner of the chassis in the rear. To prevent damage from electrostatic discharge, wear an antistatic wrist strap and connect it to one of the jacks when handling components.

To protect the modules, IOAs, and slots when installing components, observe the following guidelines:

| Caution: When handling components, use an antistatic wrist strap connected to one of the router's ESD grounding jacks. This action helps to protect the module from damage by electrostatic discharge.

| Caution: Always handle a module by its edges. Do not touch the components, pins, leads, or solder connections.

| Caution: If you meet strong resistance when attempting to seat a module using the ejectors, remove it from the chassis and confirm that the slot is designed to hold the module. Also, be sure that you have aligned the top and bottom edges in the correct matching card guides.

| Caution: Be sure to cover every empty slot with a blank filler panel to protect the system from dust or other foreign substances and to ensure proper system cooling.

| Caution: Do not discard the antistatic bag. When a module is not in use, store it in an antistatic bag.

## Required Tools and Safety Items

You need the following tools to install a line module:

- A No. 2 Phillips screwdriver
- A flathead screwdriver
- An ESD wrist strap or other grounding device