Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 
ON THIS PAGE
 

Frequently Asked Questions

Why should I use 400G transceivers?

  • Increased capacity—400G transceivers offer twice the capacity of 200G transceivers, allowing for faster data transmission.

  • Higher port density—One 400G transceiver can replace two 200G transceivers, providing a higher port density and easier aggregation.

  • Scalability—400G transceivers are compatible with upcoming network devices and can support constantly evolving deployment scenarios.

Which 400G transceivers does Juniper offer?

See Hardware Compatibility Tool for a list of all the 400G transceivers offered by Juniper, along with their detailed specifications.

Which 400G transceivers does my device support?

See Hardware Compatibility Tool for a list of the supported transceivers for your device.

Can I use a third-party transceiver with my device?

We recommend that you use only optical transceivers and optical connectors purchased from Juniper Networks with your Juniper Networks device.

CAUTION:

The Juniper Networks Technical Assistance Center (JTAC) provides complete support for Juniper-supplied optical modules and cables. However, JTAC does not provide support for third-party optical modules and cables that are not qualified or supplied by Juniper Networks. If you face a problem running a Juniper device that uses third-party optical modules or cables, JTAC may help you diagnose host-related issues if the observed issue is not, in the opinion of JTAC, related to the use of the third-party optical modules or cables. Your JTAC engineer will likely request that you check the third-party optical module or cable and, if required, replace it with an equivalent Juniper-qualified component.

Use of third-party optical modules with high-power consumption (for example, coherent ZR or ZR+) can potentially cause thermal damage to or reduce the lifespan of the host equipment. Any damage to the host equipment due to the use of third-party optical modules or cables is the users’ responsibility. Juniper Networks will accept no liability for any damage caused due to such use.

What form factors do 400G transceivers support?

Juniper supports QSFP-DD transceivers. We currently do not support OSFP transceivers.

See Quad Small Form Factor Pluggable Double Density (QSFP-DD) for details on the QSFP-DD form factor.

What speeds do 400G transceivers support?

400G transceivers can support a range of speeds, depending upon their type. They can support:

  • A single port of 400 Gbps

  • Two ports of 200 Gbps

  • Four ports of 100 Gbps

  • Eight ports of 50 Gbps

What are the different types of 400G transceivers?

400G transceivers can be classified based on their electrical and optical interface configurations.

  • Electrical Interfaces

    • 4-Lane Electrical Interface (400GAUI-4)

    • 8-Lane Electrical Interface (400GAUI-8)

  • Optical interfaces

    • Single-Lane Optical Interface

    • 4-Lane Optical Interface

    • 8-Lane Optical Interface

See 400G Optical Transceiver Flavors for details.

What standards do 400G transceivers follow?

400G transceivers and modules adhere to the IEEE 802.3-2022 standards.

Tunable DWDM optics support the OpenZR and OpenZR+ multi-source agreement (MSA) standards defined by Optical Internetworking Forum (OIF), in addition to the IEEE standards.

How are 400G transceivers different from 800G transceivers?

See Table 1 for a detailed comparison of 400G and 800G transceivers.

What does the name of the optic mean?

Optics and transceivers follow a naming convention where the product name contains the form factor, data rates, and lane distribution of the optic. See Juniper Optical Product Numbers for a detailed example.

What is the optical lane distribution on 400G transceivers?

400G optics generally use 4 parallel lanes, each of which support 100 Gbps. Multiplexing occurs over multiple fibers, parallel optics, or optical or wavelength multiplexing techniques.

What modulation techniques do 400G transceivers support?

400G optics use Pulse Amplitude Modulation 4-level (PAM4) and Non-return to Zero (NRZ) or PAM2 modulation.

PAM4 combines two bits into a single symbol with four amplitude levels, enabling you to transmit twice as much data. It has a higher required signal-to-noise ratio which requires shorter transmission distances. It requires Forward Error Correction (FEC) to handle the loss of signal integrity. FEC is enabled by default on Juniper's transceivers.

NRZ is a binary modulation format with two distinct amplitude levels within a data channel. NRZ is currently not supported on Juniper Networks optics.

See Modulation Methods for more details.

What is Digital Signal Processing (DSP)?

Digital Signal Processing techniques are used to enhance the signal integrity on optical connections and to extend the reach of optical transceivers. DSP involves components such as Serializer/Deserializer (SerDes), Feed-forward Equalization (FFE), and Decision Feedback Equalization (DFE).

What is Clock Data Recovery (CDR)?

Clock Data Recovery is the process of extracting timing information from a data signal. The receiver uses the timing information embeddded in the data signal to determine the frequency of the transmitter's clock. The receiver then uses this information to re-time the signal to ensure accurate data retrieval and transmission. CDR helps to reduce jitter and improve signal integrity and reach.

What are the components of a 400G transceiver architecture?

400G (x8) optics are composed of the following:

  • 400G Host Platform

  • 8x50 Gbps Electrical Interface

  • PAM4 Digital Signal Processor/Clock Data Recovery (DSP/CDR)

  • Drivers (8)

  • Modulators (8)

  • 4x100G Optical Interfaces

  • Transimpedance Amplifiers (TIA) (8)

  • Photo-Detectors (8)

See 400G (X8) Transceiver Architecture for a detailed explanation of each component.

What is Dense Wavelength Division Multiplexing (DWDM)?

Dense Wavelength Division Multiplexing (DWDM) uses multiple light wavelengths or channels to increase the amount of data that can be transmitted over a single optical fiber.

What are tunable DWDM transceivers?

Tunable DWDM optical transceivers use advanced modulation and equalization techniques to encode more data onto light waves and overcome transmission impairments. Tunable DWDM optics use both amplitude and phase modulation for data encoding.

Juniper's tunable DWDM optics use two types of DWDM connections:

  • Unamplified link (limited optical power)

  • Amplified link (limited optical signal-to-noise ratio and chromatic dispersion)

See Tunable DWDM Optics for more details on tunable DWDM optics.

What are ZR, ZR-M, and ZR-M-HP optics?

ZR or OIF 400ZR optics are primarily used for single-span applications due to their limited chromatic dispersion range. ZR optics use the concatenated forward error correction (CFEC) technique.

ZR-M or Open ZR+ optics are mainly used for single-span applications as they have high chromatic dispersion mitigation capabilities. They have a longer reach than ZR optics. ZR+ optics use the open forward error correction (OFEC) technique.

ZR-M-HP optics are the same as ZR-M but with higher transmission (Tx) or output power.

What are breakout capability and breakout cables?

Breakout capability is the ability to split a high-speed link into multiple smaller, lower-speed links. This is also called channelization. Breakout capability is crucial for optimizing the use of available bandwidth and physical infrastructure in various networking scenarios.

You can configure port speeds at the chassis level or the interface level. You can channelize an individual port, a block of ports, or a quad of ports.

Breakout cables have a single transceiver at one end and multiple transceivers at the other end. You can use breakout cables to physically split a single high-speed port to multiple lower-speed ports.

For more details, see Breakout Capability.

How does my device support breakout/channelization?

See Port Checker for details on channelization support for your device.

What are single-mode and multi-mode fibers?

Single-mode fibers (SMF) are designed to trasmit only one mode of an optical signal at a time. They have a core diameter of 9 microns. They have low attenuation and can support higher data rates and longer transmission distances.

Multi-mode fibers (MMF) can transmit multiple optical signals at the same time. They have a core diameter of 62.5 microns. They are easier to handle and manufacture as compared to SMF. They have higher attenuation and are used to transmit data over shorter distances.

What are the different types of cables used in 400G transceivers?

400G transceivers use direct attach cables (DAC) and active optical cables (AOC). See Cable Types and Length for details.

For a list of AOC and DAC cables supported by Juniper, see Hardware Compatibility Tool.

What are the different types of connectors used in 400G transceivers?

400G optical cables use MPO-12/APC, MPO-16/APC, duplex LC/PC, and MPO-12/BiDi/UPC connectors. See Connector Types for more details.

What is the power requirement for 400G optics?

400G QSFP-DD transceivers require between 7 to 12 W of power.

Tunable DWDM optics (ZR/ZR+) require between 18 to 23 W of power.

Can I plug an OSFP module into a QSFP-DD port?

No. OSFP and QSFP-DD refer to optics with different physical form factors.

Juniper currently does not support OSFP transceivers.

Can there be an OSFP connector on one end of an 400G link and a QSFP-DD connector on the other?

Yes. OSFP and QSFP-DD connectors can interoperate with each other on the same link, provided the Ethernet media type is the same.

Can I plug a 100G QSFP28 module into a QSFP-DD port?

Yes. The QSFP-DD ports are backward compatible with the QSFP56, QSFP28, and QSFP+ ports.

You must configure the QSFP-DD port for a data rate of 100G (or 40G) instead of 400G.