Platform Considerations
You can configure unchannelized SONET/SDH interfaces on the following E Series Broadband Services Routers:
- E120 Broadband Services Router
- E320 Broadband Services Router
- ERX1440 router
- ERX1410 router
- ERX710 router
- ERX705 router
- ERX310 router
This section describes the line modules and I/O modules that support SONET/SDH interfaces.
For detailed information about the modules that support SONET/SDH interfaces on ERX14xx models, ERX7xx models, and the ERX310 router:
- See ERX Module Guide, Table 1, Module Combinations for detailed module specifications.
- See ERX Module Guide, Appendix A, Module Protocol Support for information about the protocols and applications that SONET/SDH modules support.
For detailed information about the modules that support SONET/SDH interfaces on the E120 and E320 routers:
- See E120 and E320 Module Guide, Table 1, Modules and IOAs for detailed module specifications.
- See E120 and E320 Module Guide, Appendix A, IOA Protocol Support for information about the protocols and applications that SONET/SDH modules support.
OCx/STMx/DS3-ATM Line Modules
OCx/STMx/DS3-ATM line modules pair with OC3-4 I/O modules to deliver unchannelized OC3/STM1 ATM operation through four line interfaces.
OCx/STMx/DS3-ATM line modules pair with OC12 I/O modules to deliver unchannelized OC12/STM4 ATM operation through one line interface.
I/O modules that support single-mode (intermediate reach or long haul) or multimode operation through SC full duplex connectors are available. I/O modules that support SONET Automatic Protect Switching (APS) 1+1 redundancy and SDH Multiplex Section Protection (MSP) are also available.
Figure 5 shows the interface stack for OCx/STMx/DS3-ATM interfaces.
Figure 5: Interface Stack for OCx/STMx/DS3-ATM Interfaces

![]() | Note: For a detailed description of interface types and specifiers, see Interface Types and Specifiers in JunosE Command Reference Guide. For information about interfaces, see Planning Your Network in JunosE System Basics Configuration Guide. |
OCx/STMx POS Line Modules
OCx/STMx POS line modules pair with OC3-4 I/O modules to deliver unchannelized OC3/STM1 POS operation through four line interfaces.
OCx/STMx POS line modules pair with OC12 I/O modules to deliver unchannelized OC12/STM4 POS operation through one line interface.
I/O modules that support single-mode (intermediate reach or long haul), or multimode operation through SC full duplex connectors are available. I/O modules that support APS/MSP are also available.
Figure 6 shows the interface stack for OCx/STMx POS interfaces.
Figure 6: Interface Stack for OCx/STMx POS and OC48/STM16 Interfaces

OC48 Line Modules
OC48 line modules pair with OC48 FRAME I/O modules to deliver unchannelized OC48/STM16 POS operation through one line interface.
The OC48 I/O module supports single-mode (intermediate reach or long haul) operation through an SC full duplex connector.
The interface stack for the OC48/STM16 interfaces is the same as that for OCx/STMx POS interfaces (Figure 6).
The OC48 line module can be installed in the router’s turbo slots, numbered 2 and 4. When the OC48 line module is installed in a turbo slot, it spans slots 2–3 and 4–5. The bandwidth of slot 3 or slot 5 is used for a line module in slot 2 or slot 4 if that line module requires the turbo slot.
![]() | Note: If a line module is installed in slot 3 or slot 5, and the line module in slot 2 or 4 requires bandwidth, the system configures the line module it detects first. The state of the other line module is displayed in the show version command output as disabled (cfg error). |
OC3/STM1 GE/FE Line Module
The OC3/STM1 GE/FE line module pairs with the OC3-2 GE APS I/O module to deliver unchannelized OC3/STM1 ATM operation through two line interfaces and Gigabit Ethernet operation through one line interface.
The OC3-2 GE APS I/O module uses a range of small form-factor pluggable transceivers (SFPs) to support different optical modes and cabling distances, and accepts up to three LC-style fiber-optic connectors. You can configure ports 0 and 1 for OC3/STM1 ATM interfaces; port 2 is reserved for a Gigabit Ethernet interface.
The interface stack for OC3/STM1 ATM interfaces on the OC3-2 GE APS I/O module is the same as for OCx/STMx/DS3-ATM interfaces. (See Figure 5.)
For more information about configuring a Gigabit Ethernet interface on this I/O module, see OC3-2 GE APS I/O Modules Overview.
![]() | Note: The OC3-2 GE APS I/O module does not support APS in the current release. |
ES2 4G Line Module
The E120 and E320 routers support the ES2 4G LM. Other E Series routers do not support the ES2 4G LM. For more information about modules on the E120 and E320 routers, see the E120 and E320 Module Guide.
The ES2 4G LM supports IOAs that support single-mode operation (intermediate reach or long haul). IOAs are available in a halfheight size, which enables you to configure them in either of the two IOA bays that are available for each slot. For more information about installing IOAs, see the E120 and E320 Hardware Guide.
In the current release, the ES2 4G LM pairs with IOAs to provide OCx/STMx ATM, OCx/STMx POS, Gigabit Ethernet, 10-Gigabit Ethernet, and tunnelservice interfaces.
![]() | Note: For more information about configuring a Gigabit Ethernet interface or 10-Gigabit Ethernet interface, see Configuring Ethernet Interfaces. For more information about configuring a tunnel-service interface by using the Tunnel Server IOA, see Managing Tunnel-Service and IPsec-Service Interfaces. |
E120 Router Configuration
The 120 Gbps switch fabric of the E120 router allocates 10 Gbps of overall bandwidth to each line module slot. The line interface on the ES2 4G LM when installed in a 120 Gbps fabric configuration is 3.9 Gbps; you can achieve this rate with random packet sizes from 64–1518 bytes or a mixture of packet sizes that represent Internet mix traffic (IMIX).
E320 Router Configuration
The 100 Gbps switch fabric of the E320 router allocates 3.4 Gbps of overall bandwidth to each regular line module slot and 10 Gbps of overall bandwidth to each of the turbo slots (slots 2 and 4). The line interface on the ES2 4G LM when installed in a 100 Gbps fabric configuration is 3.4 Gbps; you can achieve this rate with packet sizes greater than 128 bytes.
The 320 Gbps switch fabric of the E320 router allocates 10 Gbps of overall bandwidth to each line module slot. The line interface on the ES2 4G LM when installed in a 320 Gbps fabric configuration is 3.9 Gbps; you can achieve this rate with random packet sizes from 64–1518 bytes or a mixture of packet sizes that represent Internet mix traffic (IMIX).
OCx/STMx ATM IOAs
The ES2 4G LM pairs with the ES2-S1 OC3-8 STM1 ATM IOA to deliver unchannelized OC3/STM1 ATM operation through eight line interfaces. You can install the ES2-S1 OC3-8 STM1 ATM IOA in both IOA bays.
The ES2 4G LM also pairs with the ES2-S1 OC12-2 STM4 ATM IOA to deliver unchannelized OC12/STM4 ATM operation through two line interfaces. You can install the ES2-S1 OC12-2 STM4 ATM IOA in both IOA bays.
The interface stack for both of these IOAs is the same as for OCx/STMx/DS3-ATM interfaces. (See Figure 5.)
OCx/STMx POS IOAs
The ES2 4G LM pairs with the ES2-S1 OC12-2 STM4 POS IOA to deliver unchannelized OC12/STM4 POS operation through two line interfaces. You can install the ES2-S1 OC12-2 STM4 POS IOA in both IOA bays.
The ES2 4G LM also pairs with the ES2-S1 OC48 STM16 POS IOA to deliver unchannelized OC48/STM16 POS operation through one line interface. In the current release, you can install the ES2-S1 OC48 STM16 POS IOA in only one of the IOA bays per slot.
Figure 7 shows the interface stack for OCx/STMx POS interfaces on the ES2 4G LM.
Figure 7: Interface Stack for OCx/STMx POS Interfaces

Numbering Scheme
When configuring or managing an interface, you must know the numbering scheme for identifying an interface. The numbering scheme depends on the type of E Series router that you have.
ERX7xx Models, ERX14xx Models, and the ERX310 Router
Use the slot/port format to identify unchannelized SONET/SDH interfaces. Interfaces that support APS/MSP also use the APS/MSP channel number.
- slot—Number of the slot in which the line module
resides in the chassis.
In ERX7xx models, line module slots are numbered 2–6; slots 0 and 1 are reserved for SRP modules. In ERX14xx models, line module slots are numbered 0–5 and 8–13; slots 6 and 7 are reserved for SRP modules. In an ERX310 router , line module slots are numbered 1–2; slot 0 is reserved for the SRP module.
- port—Number of the port on the I/O module.
On the OC3-2 GE APS I/O module, you can configure only unchannelized SONET/SDH interfaces on ports 0 and 1; port 2 is reserved for a Gigabit Ethernet interface.
On I/O modules that support APS/MSP, each primary port has a corresponding redundant port. The number of the primary port, but not that of the redundant port, is used to identify the interface. The primary port is above the corresponding redundant port on the I/O modules.
Primary port numbers range from 0 to n–1, where n is the total number of primary ports on the module. For example, if a module has one primary port, that port is labeled 0. On some I/O modules, redundant ports are labeled with a port number followed by the letter R. For example, port 3R is the redundant port for the primary port labeled 3. However, on some two-port modules, the primary port is labeled 0 and the redundant port is labeled 1.
On I/O modules that support APS/MSP, the port numbers for the working (primary) interfaces are assigned the lower half of the numbered interfaces, whereas the port numbers for the protect (redundant) interfaces are assigned the upper half of the numbered interfaces. For example, on an I/O module that provides four primary ports and four redundant ports, the working interface ports are numbered 0–3 and the protect interface ports are numbered 4–7. Similarly, on an I/O module that provides one primary port and one redundant port, the working interface is port 0 and the protect interface is port 1.
- APS/MSP channel number—Identifier
of the working or protect (redundant) interface for configuration
purposes. (See Bidirectional Switching Mode.)
The protect interface is always assigned channel number 0. The working interface is always assigned channel number 1.
See Configuring Channelized T3 Interfaces, for information about slot numbering.
For information about installing line modules and I/O modules in ERX routers, see the Installing Modules chapter in the ERX Hardware Guide.
E120 and E320 Routers
Use the slot/adapter/port format to identify unchannelized SONET/SDH interfaces.
![]() | Note: The E120 and E320 routers do not support path channelization. |
- slot—Number of the slot in
which the line module resides in the chassis.
In the E120 router, line module slots are numbered 0–5. In the E320 router, line module slots are numbered 0–5 and 11–16. For both routers, slots 6 and 7 are reserved for SRP modules; slots 8–10 are reserved for switch fabric modules (SFMs).
- adapter—number of the bay
in which the I/O adapter (IOA) resides.
This identifier applies to the E120 and E320 routers only. In the software, adapter 0 identifies the right IOA bay (E120 router) and the upper IOA bay (E320 router); adapter 1 identifies the left IOA bay (E120 router) and the lower IOA bay (E320 router).
- port—Number of the port on the IOA.
For information about installing line modules and IOAs in the E120 and E320 routers, see the Installing Modules chapter in the E120 and E320 Hardware Guide.
Interface Specifier
The configuration examples in this chapter use the format for ERX7xx models, ERX14xx models, and the ERX310 router to specify a SONET/SDH interface. (The format is described in Numbering Scheme.)
For example, the following command specifies a SONET/SDH interface on port 0 of an I/O module in slot 0.
When you configure a SONET/SDH interface on an E120 or an E320 router, you must include the adapter identifier as part of the interface specifier. For example, the following command specifies a SONET/SDH interface on port 0 of the IOA installed in the lower adapter bay (0) of slot 3.
For more information about interface types and specifiers on E Series models, see Interface Types and Specifiers in JunosE Command Reference Guide.
Exchanging Modules
If you replace an OC3 I/O module with an OCx/STMx line module and a corresponding OC3-4 I/O module or vice versa, you must erase the configuration of the existing modules. See slot accept in JunosE System Basics Configuration Guide.
On the E120 and E320 routers, if you replace an ES2-S1 OC3-8 STM1 ATM IOA with an ES2-S1 OC12 STM4 POS IOA, you must erase the configuration of the existing IOA. See adapter accept or slot accept in chapter Managing Modules JunosE System Basics Configuration Guide.