Juniper Networks

About this Document

This document presents a Juniper Validated Design (JVD) for Data Center Interconnect (DCI) using Internet Protocol over Dense Wavelength-Division Multiplexing (IPoDWDM) with Juniper ACX7000 Router Series, MX Series Router, and PTX Series Router, and Juniper 400G Coherent Optics as transceivers.

This document focuses on demonstrating the capabilities of Juniper 400G Coherent Optics and validating the IPoDWDM solution with Juniper's Routing Platforms and ADTRAN Open Line System (OLS).

Solution Benefits

Juniper Networks Validated Designs provide a comprehensive, end-to-end blueprint for deploying Juniper solutions. These designs are created by Juniper's expert engineers and tested to ensure they meet requirements, reducing the risk of costly mistakes, saving time and money, and optimizing network performance.

Juniper Converged Optical Routing Architecture

Traditional DWDM networks use transponders to convert Ethernet signals into a DWDM signal. Converged Optical Routing Architecture (CORA) integrates DWDM optics directly into Juniper routers and switches. This eliminates the need for a separate optical transponder, allowing the Internet Protocol (IP) and optical network management to operate as a single domain controller.

• Lowers capex by eliminating optical transponders.
• Simplifies operations and lowers operational expenses.
• Increases network efficiency.
• Lowers power consumption.
• Allows the router to monitor DWDM link performance.
• Enables the router to make routing decisions based on DWDM link performance.
• Facilitates faster troubleshooting and reduces downtime.

Use Case and Reference Architecture

DCI requires high-capacity transport interconnecting two or more data centers. This solution focuses on high-capacity transport using an IPoDWDM network, referred to as CORA by Juniper. Design validation ensures reliable operations of coherent optical transceivers tightly coupled with router hardware and software.

IPoDWDM Network Diagram

The IPoDWDM network consists of packet-optical convergence, 400G ZR/ZR+ transceivers, booster amplifiers, preamplifiers, and ROADM/passive filters. IP-Optical Management oversees the network, connecting data centers via multiple wavelengths over a single pair of fibers, with components like N x ILAS (Inline Amplifier System).

Validation Framework

This JVD addresses the modernization of the transport layer by testing the capabilities of Juniper 400G Coherent Optics (JCO400). Key technical attributes include:

• For Amplified Links: Minimum receives Optical Signal-to-Noise Ratio, Maximum receives Chromatic Dispersion.
• For Unamplified Links: RX Sensitivity.
• Telemetry.
• Junos and Junos Evolved Software Support.
• Configurability.
• Performance Monitoring.

Test Bed

Amplified Test Bed

The amplified test bed utilizes three coherent optical transceivers (TRX) in DCI1 and DCI2 routers. All transceivers and ROADM ports are tuned to specific wavelengths. Signals with different wavelengths are multiplexed into a single fiber pair. For most test cases, one transceiver is the unit under test, with others acting as aggressors. Amplifiers add noise, reducing the Optical Signal-to-Noise ratio, which is emulated using amplified spontaneous emission (ASE). Chromatic Dispersion (CD), caused by light scattering in fiber optic cables, is compensated by the transceiver's digital signal processor (DSP) up to a certain limit. Chromatic dispersion emulators are used to simulate fiber optic cable distance.

Unamplified Test Bed

The unamplified test bed uses two pairs of fiber optical cables, each carrying two wavelengths. A 50/50 Optical Splitter/Combiner merges these wavelengths. Two coherent optical transceivers are used on DCI1 and DCI2 routers, and four on DCI3. For unamplified or dark fiber links, the design is limited by optical power. Span Loss, due to light scattering, is the primary factor, affecting the link budget, which is determined by Transmit Power and Receiver Sensitivity. A Variable Optical Attenuator (VOA) is used to emulate span loss.

Platforms / Devices Under Test (DUT)

• DCI1: PTX10001-36MR
• DCI2: MX304
• DCI3: ACX7100-48L

Test Bed Configuration

Configuration Template for Junos Evolved Platforms

interfaces {
  $INTERFACE_NAME$ {
    speed $PORT-SPEED$;
    number-of-sub-ports $NUMBER-OF-CHANNELS$;
    optics-options {
      wavelength $WAVELENGTH$;
      tx-power $TX-POWER$;
    }
  }
}

NOTE: For channelized interfaces, optics-options are configured on the first sub-port (et-x/y/z:0), not on the parent port (et-x/y/z). The speed and number-of-subports knobs are still configured under the parent port.

Configuration Template for Junos Platforms (Chassis)

chassis {
  fpc $FPC$ {
    pic $PIC$ {
      port $PORT$ {
        speed $PORT-SPEED$;
        number-of-sub-ports $NUMBER-OF-CHANNELS$;
      }
    }
  }
}

interfaces {
  $INTERFACE_NAME$ {
    optics-options {
      wavelength $WAVELENGTH$;
      tx-power $TX-POWER$;
    }
  }
}

NOTE: For channelized interfaces, optics-options are configured on the first sub-port (et-x/y/z:0), not on the parent port (et-x/y/z).

Configuration Template for ADTRAN FSP3000C Open Line System

Amplifier: AM-S23L
Optical Multiplexer/Demultiplexer (Mux/Demux): RD-12RS

### The commands needs to be executed in sequence
set interface 1/$ROADM_SLOT_NUM$/n/oms oms carrier-power-management setpoint-psd -35
set interface 1/$ROADM_SLOT_NUM$/$CLIENT_PORT_NUM$/oms is-substates append mt
set interface 1/$ROADM_SLOT_NUM$/$CLIENT_PORT_NUM$/oms carrier-power-management powerset-configuration enable setpoint-psd -24
set interface 1/$ROADM_SLOT_NUM$/$CLIENT_PORT_NUM$/oms oms is-substates remove all
set fiber a-end 1/$ROADM_SLOT_NUM$/n z-end 1/$PREAMP_SLOT_NUM$/n
set fiber a-end 1/$PREAMP_SLOT_NUM$/c z-end 1/$BOOSTER_SLOT_NUM$/c
commit

### Assign one Arbitary_Service_Number per Client_Port per Center Frequency then configure multiple instances as per below template
set interface 1/alien/$ARBITARY_SERVICE_NUMBER$
set interface 1/alien/$ARBITARY_SERVICE_NUMBER$/otsi >>
set otsi $ARBITARY_SERVICE_NUMBER$ center-frequency $CLIENT_PORT_FREQUENCY_THZ$ bandwidth $CLIENT_PORT_BANDWIDTH_GHZ$
done
commit
set fiber a-end 1/alien/$ARBITARY_SERVICE_NUMBER$ z-end 1/$ROADM_SLOT_NUM$/$CLIENT_PORT_NUM$/
commit
set croma slc $ARBITARY_SERVICE_NUMBER$ >>
set slc-aendpoint path-node-number 2
set slc-zendpoint path-node-number 1
set slc-aendpoint slc-active-endpoint slc-resource-instance $DEGREENUMBER$
set slc-zendpoint slc-active-endpoint slc-resource-instance 1/alien/$ARBITARY_SERVICE_NUMBER$/otsi
done
commit
set croma slc $ARBITARY_SERVICE_NUMBER$ slc-zendpoint admin is
commit
run execute interface 1/$ROADM_SLOT_NUM$/n/oms oms carrier-power-management equalize
run execute interface 1/$ROADM_SLOT_NUM$/n/oms oms degree-span-equalization start-span-initialization
set croma slc $ARBITARY_SERVICE_NUMBER$ slc-aendpoint admin is
commit
run execute interface 1/$ROADM_SLOT_NUM$/$CLIENT_PORT_NUM$/oms oms carrier-power-management powerset

Contact your Juniper representative to obtain ADTRAN representative for support. For full configurations used in this validation, see Juniper GitHub.

Test Objectives

Test Goals

• Validate end-to-end optical architecture and design with coherent optics over DWDM line systems as foundation technology under scale at the time of normal operations and under multiple stress conditions.
• Validate performance monitoring functionality through streaming telemetry.
• Validate TCAs being triggered.
• Validate PTX10001-36MR as a DCI router.
• Validate MX304 as a DCI router.
• Validate ACX7100-48L as a DCI router.
• Validate JCO400-QDD-ZR-M-HP and QDD-400G-ZR-M-HP as TRX for amplified and unamplified use cases.
• Validate ADTRAN's Open Line System.

Test Non-Goals

• Controller that can monitor both router and Open Line System (OLS) where AI can detect anomaly.
• Management of the Open Line System (OLS).
• Precision Time Protocol (PTP) and synchronization.

Results Summary and Analysis

General testing includes the following crucial scenarios:

• Frequency/wavelength sweep ensuring the router can configure on the entire C-band correctly.
• Noise or Optical Signal-to-Noise Ratio (OSNR) tolerance test for Amplified links.
• Chromatic Dispersion with Noise or OSNR tolerance test for Amplified links.
• Rx Sensitivity test for Unamplified links.
• Fiber cuts.
• Aggregated Ethernet (AE) mixed speeds.
• Telemetry tests.
• Netconf Optical PMs Path tests.
• Open JTS tests.
• Device Reboots.
• Various Junos OS and Junos OS Evolved software components restart.
• BGP tests.
• OSPF tests.
• BFD tests.

Recommendations

• Continuously monitor the optical Performance Monitoring (PM) values to ensure optical performance and corrective actions can be done.
• Juniper does not sell Open Line Systems (OLS). However, this document proves that any third-party OLS (with channel spacing of 75GHz and above for 400G coherent signals) works well with Juniper Coherent Optics and Routers. Since ADTRAN was used for this validation, Juniper recommends using ADTRAN Open Line Systems for the IPoDWDM solution. Contact your Juniper representative to connect them with an ADTRAN representative.
• For brownfield deployments, it is recommended to contact the existing OLS vendor to check the feasibility of the link using the results of this document.

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