Cisco Carrier Routing System

Cisco CRS 1-Port 100 Gigabit Ethernet Coherent DWDM Interface Module Data Sheet

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This data sheet provides detailed product specifications for the Cisco® IP over Dense Wavelength-Division Multiplexing (IPoDWDM) solution, the Cisco CRS 1-Port 100 Gigabit Ethernet Coherent DWDM Interface Module (Figure 1). The module connects directly into any DWDM network and provides up to 100 Gbps of data throughput, transporting 100 Gigabit Ethernet LAN Physical Layer (LAN-PHY) and Optical Transport Network (OTN) Transport Unit Level 4 (OTU-4) over a 50-GHz spaced, 50-GHz stabilized, ITU-compliant wavelength. The module is completely tunable across the C band in the ITU 50-GHz grid. The unit uses a Coherent Polarization-Multiplexed Differential Quadrature Phase Shift Key (CP-DQPSK) modulation scheme that is based on the Optical Internetworking Forum (OIF) standard.

Figure 1.      Cisco CRS 1-Port 100 Gigabit Ethernet Coherent DWDM Interface Module

Challenge and Solution

The bandwidth carried on core and metropolitan (metro) DWDM networks is growing exponentially, while operators’ revenues are not growing as quickly. The Cisco CRS 1-Port 100 Gigabit IPoDWDM solution can dramatically lower the cost to carry bandwidth, helping to maintain and improve customers’ profitability in the face of exponential Internet growth due to demand for next-generation services such as Quad play (data, voice, video, and mobility), video distribution, Internet Protocol Television (IPTV), and other high-bandwidth services.

The possibility of transmitting 100-Gbps wavelengths on existing or new Greenfield DWDM systems improves return on investment by increasing the overall capacity per fiber pair without impacting the unregenerated transmission distance, which can be covered through the advance modulation schemes. The scale of 10 Gbps to 40 Gbps and now to 100 Gbps multiplies by a factor of 10 the bandwidth that can be transported over existing fiber networks.

The new Coherent Polarization-Multiplexed Differential Quadrature Phase Shift Key (CP-DQPSK) modulation enables 100-Gbps capacity transmission over existing 10/40-Gbps networks, up to 3000 km, thus enabling Ultra Long Haul (ULH) networks of unregenerated optical links.

The new interface module is designed to provide the following benefits:

   Transport of 100-Gbps wavelengths over fully uncompensated networks, up to 3000 km of unregenerated optical links

   Transport at 100 Gbps over very low-quality fiber with very high Polarization Mode Dispersion (PMD)

   Transport of 100-Gbps wavelengths over existing 50-GHz channel spacing with very high tolerance to filtering penalties

This module helps service providers increase efficiency, improve reliability, and reduce operational and capital costs by eliminating expensive and bulky optical transponder equipment.

Enhanced Forward Error Correction Capability

This module can support a Forward Error Correction (FEC) mechanism. The trunk port supports three software- configurable FEC coding options.

   Generic FEC (GFEC): Standard G.975 Reed-Salomon algorithm with 7 percent overhead.

   Ultra FEC (UFEC): Standard G.975.1 (Sub-clause I.7) with 20 percent overhead. This FEC scheme uses two orthogonally concatenated BCH Enhanced FEC (EFEC) codes. The constructed code is decoded iteratively to rebuild the original frame.

   High-Gain FEC (HG-FEC): High-Gain EFEC with 7 percent overhead, providing better performances than standard G.975.1 7 percent OH FEC. Because of the reduced overhead and lower bit rate, HG-FEC is suitable for all the applications where 100 Gbps wavelengths are passing through a high number of reconfigurable optical add-drop multiplexer (ROADM) nodes with limited pass-band performances.

The different FEC modes extend the reach of the DWDM signal up to 3000 km without requiring signal regeneration. For more information about the Cisco CRS or about other interfaces available for the Cisco CRS, visit:

Protocol Transparency

The module can transparently deliver any 100-Gbps services for cost-effective, point-to-point networking for the Cisco CRS platform (see Table 1).

Table 1.       Transponder Client Configurations and Mapping





Rate (Gbps)


Rate with 7% GFEC or EFEC OH (Gbps)

Rate with 20% UFEC OH (Gbps)



Bit transparent through standard G.709v3 mapping






Transparent G.709 standard


Advanced Modulation Scheme

The Cisco CRS 1-Port 100 Gigabit Ethernet Coherent DWDM Interface Module features an advanced modulation scheme to provide optical performances significantly better than industry-standard 10-Gbps equivalent interfaces.

Cisco selected a CP-DQPSK modulation format to optimize 100-Gbps transmission in terms of Optical Signal-to-Noise Ratio (OSNR), Chromatic Dispersion (CD), and Polarization Mode Disperson (PMD) robustness.

The CP-DQPSK modulation scheme consists of multiplexing two DQPSK signals using two different orthogonal light polarizations, as shown in Figures 2 and 3.

Figure 2.      CP-DQPSK Logical Modulation Scheme

Figure 3.      CP-DQPSK Logical Transmitter Scheme

The core of the 100-Gbps CP-DQPSK modulation scheme is the optical receiver, based on coherent optical detection, where a Digital Signal Processor (DSP) calculates the inverse of the optical system matrix, allowing the receiver to recover the original transmitted signals (Figure 4).

Figure 4.      CP-DQPSK Logical Receiver Scheme

The main benefits of CP-DQPSK are:

   Strong OSNR performance

   Outstanding CD robustness, eliminating the need for any optical chromatic dispersion compensation solution

   Extended PMD robustness (three times better than 10-Gbps units)

   Very high spectral efficiency, allowing 100-Gbps wavelengths to be transmitted across a high number of ROADMs with negligible penalty

Performance Monitoring

The 100-Gbps DWDM module provides support for both transparent and non-transparent signal transport performance monitoring. The digital wrapper channel is monitored according to G.709 (OTN) and G.8021 standards. Performance monitoring of optical parameters on the client and DWDM line interface include Loss Of Signal (LOS), laser bias current, transmit optical power, and receive optical power. Calculation and accumulation of the performance monitoring data are supported in 15-minute and 24-hour intervals as per G.7710.

Physical system parameters measured at the wavelength level, such as mean PMD, accumulated CD or received OSNR, are also included in the set of performance monitoring parameters. These can greatly simplify troubleshooting operations and enhance the set of data that can be collected directly from the equipment. A detailed list of performance monitors is given in Table 6.

The module incorporates faceplate-mounted LEDs to provide a quick visual check of the operational status of the card.

Product Specifications

Table 2 gives specifications of the Cisco CRS 1-Port 100Gigabit Ethernet CP-DQPSK Full C-Band Tunable DWDM Interface Module.

Table 2.       Product Specifications



Chassis compatibility

Compatible with all current Cisco CRS-1 and CRS-3 line-card chassis

Software compatibility

Cisco IOS® XR Software Release 4.2.3 or later for CRS-3


  100 Gigabit Ethernet
   Encapsulations: ARPA, IEEE 802.2/SAP, IEEE 802.3/SNAP
   IEEE 802.x flow control
   802.1q VLAN support, jumbo frames
   IEEE 802.1p tagging
  Source and destination MAC accounting and VLAN accounting

Port density

One interface module per physical layer interface module (PLIM)

POS feature summary

Not applicable

OTN (G.709) feature summary

  ITU G.709
  Alarm reporting: Loss of Signal (LOF), Loss of OTN Frame (LOF), Loss of OTN Multiframe (LOM),
  OTU alarm indication signal (OTU-AIS), OTU backward defect indication (OTU-BDI), ODU alarm indication signal (ODU-AIS), ODU open connection indication (ODU-OCI), ODU locked (ODU-LCK), ODU backwards defect indication (ODU-BDI), ODU payload type identifier mismatch (ODU-PTIM), OTU signal fail (OTU_SF_BER) and OTU signal degrade (OTU_SD_BER)
  OTU_SF_BER and OTU_SD_BER alarms are based on monitoring OTU BIP errors with a user-configurable threshold crossing
  Error counts: OTU BIP, OTU BEI, ODU BIP, and ODU BEI
  Threshold crossing alerts (TCAs) for OTU BIP errors (SM-TCA) and ODU BIP errors (PM-TCA) with user-configurable threshold
  Local (internal) and line (network) loopback

FEC feature summary

  GFEC - G.975.1 – Reed Salomon with 7% Over Head (OH)
  HG – FEC – High Gain FEC with 7% OH
  UFEC – Ultra FEC with 20% OH – two orthogonally concatenated BCH super FEC codes
  FEC statistics for pre-FEC BER, Q, Q Margin, corrected errors (EC) and uncorrected words (UC)

Optical feature summary

  Line rate 111.809Gbps or 27.952 Gbaud +/-20ppm (7% FEC OH) and 124.964Gbps or 31.241Gbaud +/-20ppm (20% OH)
  Duplex LC faceplate optical connector
  Electronically compensated CD (70,000ps/nm) and DGD (180ps)
  Full C-band tunable laser – 1528.77 to 1566.72nm in 50GHz grid
  Tx optical power (-1dBm to +1.5dBm)
  Tx and Rx optical power monitoring
  Optical power monitoring accuracy +/–1 dB

Reliability and availability

  Online insertion and removal (OIR) without affecting system traffic

Network management

  Cisco IOS XR Software command-line interface (CLI)
  Simple Network Management Protocol (SNMP)
  Extensible Markup Language (XML) interface
  CraftWorks Interface (CWI)

Physical dimensions

  Occupies one PLIM slot
  Weight: 8.6 lb (3.9 kg)
  Height: 20.6 in. (52.32 cm)
  Depth: 11.2 in. (28.4 cm)
  Width: 1.8 in. (4.57 cm)



Latency (End to End)

  G.709 – Standard FEC: 4 microseconds
  G.709 – HG-FEC 7%: 20 microseconds
  G.709 – UFEC 20%: 39 microseconds

Environmental conditions

  Storage temperature: –40 to 70°C (–40 to 158°F)
  Operating temperature:
   Normal: 0 to 40°C (32° to 104°F)
   Short-term: –5 to 55°C (23 to 131°F)
  Relative humidity:
   Normal: 5 to 85%
   Short-term: 5 to 90% but not to exceed 0.024 kg water/kg of dry air

Short-term refers to a period of not more than 96 consecutive hours and a total of 360 hours, but not more than 15 instances in 1 year.


Approvals and Compliance

Table 3 gives standards compliance information and Table 4 provides additional specifications.

Table 3.       Compliance and Agency Approvals



Safety standards

  UL/CSA/IEC/EN 60950-1
  IEC/EN 60825 Laser Safety
  ACA TS001
  AS/NZS 60950
  FDA–Code of Federal Regulations Laser Safety


  FCC Class A
  ICES 003 Class A
  AS/NZS 3548 Class A
  CISPR 22 (EN55022) Class A
  VCCI Class A
  BSMI Class A
  IEC/EN 61000-3-2: Power Line Harmonics
  IEC/EN 61000-3-3: Voltage Fluctuations and Flicker

Immunity (basic standards)

  IEC/EN-61000-4-2: Electrostatic Discharge Immunity (8-kV contact, 15-kV air)
  IEC/EN-61000-4-3: Radiated Immunity (10V/m)
  IEC/EN-61000-4-4: Electrical Fast Transient Immunity (2-kV power, 1-kV signal)
  IEC/EN-61000-4-5: Surge AC Port (4-kV CM, 2-kV DM)
  IEC/EN-61000-4-5: Signal Ports (1 kV)
  IEC/EN-61000-4-5: Surge DC Port (1 kV)
  IEC/EN-61000-4-6: Immunity to Conducted Disturbances (10 Vrms)
  IEC/EN-61000-4-8: Power Frequency Magnetic Field Immunity (30A/m)
  IEC/EN-61000-4-11: Voltage Dips, Short Interruptions, and Voltage Variations


  EN300 386: Telecommunications Network Equipment (EMC)
  EN55022: Information Technology Equipment (Emissions)
  EN55024: Information Technology Equipment (Immunity)
  EN50082-1/EN-61000-6-1: Generic Immunity Standard

Network Equipment Building Standards (NEBS)

This product is designed to meet the following requirements (qualification in progress):

  SR-3580: NEBS Criteria Levels (Level 3)
  GR-1089-CORE: NEBS EMC and Safety
  GR-63-CORE: NEBS Physical Protection

All specifications in Table 4 are worst-case for the operational life of the product.

Table 4.       Additional Specifications: DWDM Line Interface


DWDM line interface

Connector type


Target distance

3000 km (dependant on network configuration)

Bit rate

27.952 Gbaud ±20 ppm (OTU4 with GFEC or HG-FEC 7% OH)

31.241Gbaud ±20 ppm (OTU4 with UFEC 20% OH)

Automatic laser shutdown and restart

ITU-T G.664 (06/99)

Nominal wavelengths (lTnom)

Full tunable between 1528.77 and 1566.72nm (C-Band – 50 GHz)

Connector type (TX/RX)

LC, duplex (shuttered)


Power range

–1 dBm to +1.5 dBm

Wavelength range

Full tunable from 1528.77 nm to 1563.86 nm across 50GHz ITU grid



Minimum Optical Return Loss (ORL)

27 dB

Laser safety class



P (RMax) (minimum overload)

0 dBm

Chromatic dispersion tolerance (0.5 dB penalty)

–70,000 to +70,000 ps/nm

PMD tolerance (0.5 dB penalty)

30 ps, 1 X 10-5 outage probability

OSNR (back to back) (0.1 nm Res. BW)

7.5 dB (1 X 10^-15 Post FEC BER) (see Table 5)

Receiver reflectance (maximum)

30 dB

Input wavelength bandwidth (lc_rx)

Between 1528.77 and 1566.72 nm (C-Band – 50 GHz)

Single-channel optical link (without DWDM)2

Fiber type

G.652 (SMF), G.653 (DSF) and G.655 (NZ-DSF)

Sensitivity (over dark fiber)

–22 dBm (1 X 10^-15 Post FEC BER)3

Link budget (no amplification)

28 dB

Optical path penalty

1 dB

Path length

80 km (G.652/G.655); 100 km (G.653)4


Optical power monitoring

Tx and Rx, ±1 dB accuracy

1 Must change RxLOS threshold default from –19.5 dBm to –23.5 dBm.

2 Please contact your Cisco representative for the Application Note on 40 Gbps single-channel CRS-1 interconnection extending to 80 km and beyond.

3 Must change default RxLOS to -30 dBm or less, wavelength set to a channel between 7 and 14 (1531.116 nm and 1533.858 nm)

4 Proper system design required; network may require Dispersion Compensating Units

Table 5.       DWDM Receive-Side Optical Performances

CD Tolerance

FEC Type



Input Power Sensitivity


(0.1 nm RBW)

Extended performance

0 ps/nm

(20% OH)



0 to –14 dBm

(-20dBm with 0.5dB of OSNR penalty)

7.5 dB

0 ps/nm

180 ps

8.0 dB

+/- 70,000 ps/nm

180 ps

9.0 dB

0 ps/nm

(7% OH)



0 to –14 dBm

(-20dBm with 0.5dB of OSNR penalty)

8.0 dB

0 ps/nm

180 ps

8.5 dB

+/- 70,000 ps/nm

180 ps

9.5 dB

Table 6.       Performance Monitoring Parameters


Parameter Name








Number of background block errors



Background block error ratio



Number of errored seconds



Errored seconds ratio



Number of severely errored seconds



Severely errored seconds ratio



Number of unavailable seconds



Number of failure counts


Bit errors

Number of corrected bit errors

Uncorrectable words

Number of uncorrectable words

Trunk optical PM


Transmit optical power


Transmitter laser bias current


Receiver optical power


Residual chromatic dispersion


Mean polarization mode dispersion


Optical signal-to-noise ratio, calculated with 0.5 nm RBW

Ordering Information

To place an order, contact your local Cisco representative or visit the Cisco Ordering Home Page, Use the ordering information in Table 7.

Table 7.       Ordering Information

Product Part Number

Product Name

1-100GE-DWDM/C (=)

Cisco CRS 1-Port 100Gigabit Ethernet CP-DQSPK Full C-Band Tunable DWDM Interface Module

Service and Support

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For More Information

For more information about the Cisco CRS 1-Port 100Gigabit Ethernet CP-DQPSK Full C-Band Tunable DWDM Interface Module, contact your local Cisco representative or visit: