21Sep, 2023
    Optical Modules FAQs — Part 2

    In the dynamic realm of optical networking, real-world challenges often test the capabilities of both original equipment manufacturer (OEM) and third-party modules. These challenges encompass issues like unresponsive ports, fluctuating links, CRC errors, packet loss, module failures, and sudden downtimes. To assist and enlighten our community, we’ve compiled essential answers to these common queries:

    Q1: High Prices of OEM Modules — Are They Justifiable? Do You Really Need Them?

    A1: The soaring prices of OEM modules may raise eyebrows, with a part of the cost aimed at providing assurance, and another part for profit. Yet, OEM modules indeed guarantee superior quality and compatibility, potentially avoiding disruptive issues. Juggling various third-party modules based on cost alone can lead to complications. Some third-party optical modules maintain robust quality control and compatibility testing. The choice depends on your priorities and operational capabilities.

    Q2: Manufacturer Size — Does Bigger Mean Better Quality?

    A2: For well-established modules, the difference between large and small manufacturers is subtle, mostly evident in extreme cases. Regardless of size, it’s crucial that both manufacturers ensure compatibility with your specific equipment.

    Q3: AOC Compatibility Troubles — Whose Responsibility Is It?

    A3: When AOC (Active Optical Cable) connections between different manufacturers don’t function as expected, both parties share the responsibility. To avoid such scenarios, clarify the type of equipment on the other end and whether pre-coding is necessary before procuring AOC/DAC (Direct Attach Cable).

    Q4: Deciphering Optical Module Transmission Distance

    A4: Optical module and AOC transmission distances are primarily determined by the modules themselves, with equipment playing a smaller role. However, for modules that support Forward Error Correction (FEC), both the module and the equipment must be FEC-compatible to achieve extended distances. For example, without FEC, some 40G single-mode modules can only transmit up to 30km, but with FEC support, they can reach 40km.

    Q5: Critical Parameters for Long-Distance Single-Mode Optical Modules

    A5: When purchasing 40km/80km optical modules, don’t solely rely on the advertised distance or actual fiber length. Consider both the claimed receiving sensitivity and real-world line attenuation to ensure that the specified 80km optical module indeed performs as expected.

    Q6: Demystifying the 1-to-4 Cable

    A6: Nearly all 40G QSFP+ ports can be configured to split one 40G connection into four 10G links. Similarly, most modern 100G QSFP28 ports support configuration to split one 100G into either four 10G or four 25G connections. The two types of 1-to-4 cables are DAC and AOC, alongside modules and separate fiber optics.

    Q7: Compatibility Codes and Model Differences

    A7: Some module compatibility issues may arise due to changes in compatibility code verification mechanisms between different models. Model 2 network cards may necessitate compatibility codes, while Model 1 did not.

    Q8: Third-Party Modules and Device Compatibility

    A8: Issues with third-party modules not functioning on specific devices may stem from the modules being compatibility-tested with other devices but not the one in question. Compatibility extends beyond coding to various signal specifications.

    Q9: Unilateral UP Status — Is This Normal?

    A9: It’s common for one end to be UP while the other remains unresponsive. Transmit and receive functions operate independently.

    Q10: Tackling Packet Loss and CRC Errors

    A10: When encountering packet loss and CRC errors, it’s essential to note that ports receiving CRC errors are receiving them from the other end. Investigate the equipment on the opposite side and the line, particularly if third-party devices are involved.

    Q11: Diagnosing Unresponsive Ports

    A11: Unresponsive ports can result from various factors such as mismatched auto-negotiation settings, temperature fluctuations, compatibility issues between modules and equipment, incompatibility at either end of the equipment, optical fiber problems, coding discrepancies, FEC settings, excessive optical attenuation, and device-specific behaviors like loop protection and link jitter protection.

    2Sep, 2023
    Q&A for GIGALIGHT 400G Optical Modules

    GIGALIGHT 400G transceivers offer customers a wide variety of super high-density 400 Gigabit Ethernet connectivity options for data centers, enterprise networks, and service provider applications. Here is a list of FAQs about our new generation of 400G transceiver modules.

    Q: What 400G transceivers are available from GIGALIGHT?

    A: GIGALIGHT supports a full range of 400G optical transceivers in QSFP-DD form factors, 400G AOCs and DACs, and 400G breakout cables. The tables below summarize the 400G connectivity options GIGALIGHT supports.

    Q: What are the benefits that GIGALIGHT 400G transceivers can offer?

    A: GIGALIGHT 400G transceivers help cloud operators, service providers, and enterprises to achieve higher bandwidth at lower cost and power per gigabit. Key benefits of GIGALIGHT 400G transceivers include:

    1. With QSFPDD form factors to meet your diverse needs of ramping up to 400G transmission.
    2. SiPhbased technology used on some GIGALIGHT 400G transceivers for lower power & cost and higher density.
    3. Compliant with QSFPDD MSA and IEEE 802.3bs, and tested in host devices for proven interoperability, superior performance, quality, and reliability.
    4. Compatible with mainstream brands such as Cisco, Juniper, Arista, Dell, Mellanox, etc.
    5. Simplify your network by reducing the number of optical fiber links, connectors and patch panels by a factor of 4.

    Q: What are the application scenarios of GIGALIGHT 400G transceivers?

    A: 400G QSFP-DD transceiver modules are the backbone of high-performance 400G networks. GIGALIGHT 400G transceivers can be used in various scenarios. Generally speaking, it depends on the connection distance you want to cover. For example, you can use 400G DAC and AOC cables for shortreach connections between ToR switch and server. For 2km to 10km data center interconnection connections, QSFP-DD FR4 or LR4 modules are better high-quality and economical choices.

    Q: What quality certifications do you have for your 400G transceivers?

    A: GIGALIGHT 400G transceivers accord with a range of certifications for optical transceivers including ISO 9001:2015, RoHS, REACH, CB, RCM, FCC certificate (EAC Certificate). Rest assured that our products will meet essential quality and safety requirements.

    Q: Are GIGALIGHT 400G transceivers compatible with Cisco or Juniper brands?

    A: Many of our 400G transceiver modules are compatible with Cisco, Juniper, Arista, Dell, Mellanox, etc. You can always ask for a compatibility test before the purchase to check whether our transceiver is compatible with your devices. If you’re deploying a larger network or upgrading your current data center architecture, compatible transceiver modules may come in handy as they can be immediately installed without compatibility problems and fit right into your data center infrastructure.

    Q: Can I plug GIGALIGHT OSFP module into a 400G QSFP-DD port, or GIGALIGHT QSFP-DD module into an OSFP port?

    A: No. OSFP and QSFP-DD are two physically distinct form factors. If you have an OSFP system, then GIGALIGHT 400G OSFP modules must be used.

    Q: Can I return the product or get a refund?

    A: GIGALIGHT wants you to be thrilled with our 400G transceiver modules. However, if you need to return an item or ask to get a refund, we’re here to help. For all 400G transceiver modules, DAC & AOC cables, and breakout cables, you have 30 calendar days to return an item from the date you received it, which means the request must be submitted within the return/exchange window. Refunds will be processed after GIGALIGHT receives and inspects the returned items.