Cisco ONS 15454 Series Multiservice Provisioning Platforms

Field Notice: ONS 15454 OC-192 Optical Connector Compatibility Brief

Revised June 12, 2003

April 12, 2002

Products Affected


Top Assembly

Part Number

ONS 15454-OC192LR1550=


Problem Description

ONS 15454 OC-192 optical boards exhibit the following mechanical connector issues when you use incompatible attenuators and connectors:

  • Insufficient attenuator engagement.

  • Locked connection after full connector insertion.

  • Fiber jumper locks into connector and cannot be removed.


With the higher power optics in the OC192, specifications IEC 825 & EN60825 required the incorporation of a shutter mechanism to protect the user from laser light sources. To address this issue, a new SC duplex adapter was developed. Design requirements led to a depth of the SC mechanism of 3 millimeters (mm) deeper than previous versions.

  1. The added SC adapter length of 3 mm causes certain attenuators to fail to lock into place.

  2. There are mechanical inconsistencies with fiber optic connectors between some manufacturers. If an incompatible fiber optic connector is fully inserted, the connector may seize in place. This seizure makes connector removal difficult. In extreme cases, you need to use pliers for removal.

Note:?Forced removal of a locked connector can cause damage to the shutter mechanism. Do not use a connector with a damaged shutter; the connector does not provide the intended safety feature. Refer to the number "2" issues that precede and follow.

Problem Symptoms

  1. Insufficient engagement (no click) of attenuators. Connectors can fail to maintain secure connection.

  2. Mechanical retention force is higher than specified. Difficulty with the removal of mating connectors can require the use of tools to remove mating connectors. The use of tools can result in damage to the shutter mechanism.


Cisco is working with connector manufacturers to develop a permanent solution. The solution will be incorporated when available. Cisco offers these interim solutions to aid users to overcome these limitations. These issues affect the industry as a whole; do not consider the issues unique to Cisco. Updates will be provided as these solutions are closer to implementation.

  1. Testing shows that you can overcome this issue with the use of specific attenuators, and/or a combination of attenuator and patch cord.

    Two attenuators have been identified that provide acceptable operation:

    • Aria Technologies

      Livermore, CA


    • P/N (Description)

      ATN-2-35-05-15mm (5bd Attenuator (15mm))

      ATN-2-35-10-15mm (10bd Attenuator (15mm))

      ATN-2-35-15-15mm (15bd Attenuator (15mm))

      ATN-2-35-20-15mm (20bd Attenuator (15mm))

    When you use the ONS 15454 front door, use only the Aria attenuator. In all cases, ensure that the attenuator is fully seated and locked.

  2. Comprehensive testing has been done to determine which connectors do, and do not, exhibit the connector-lock issue. You can avoid the issue if you use connectors from the compatible list that follows.

    Note:?Cisco plans to implement a new bulkhead in the near future that removes this restriction.

    This list of manufacturer connectors are compatible with the SC connector used on the OC-192:

    • Amphenol Fiber Optic Products

    • ADC Telecommunications

    • AFOP (Alliance Fiber Optic Products)

    • Diamond**

    • Fibersource International/Suncall

    • Molex

    • Senko Advanced Components

    • Seiko Instruments

    • Seiko Geiken

    • Tyco/AMP*

    • UConn

    • 3M*

Note:?* These two suppliers had previously been on the unacceptable list because of the slots located on the bottom of the coupling sleeve. The slots interfered with the shutter.

Note:?** The product from this supplier was not tested, but the connector form factor was evaluated from a datasheet and was deemed acceptable.

These are SC connector suppliers with products that do NOT work with the new connector:

  • AT&T

  • Corning/Siecor

  • Lucent

Important Notes:

  • All suppliers may offer multiple variations of the SC connector. The SC connector variation that does not work is the one that has the extra protrusions on the coupling sleeve.

  • Ensure strict adherence to the product documentation and any related release notes.

  • The observations and recommendations should in no way be construed as a negative evaluation of competitor products but, rather, as a determination of compatibility.

  • Despite a comprehensive review of the SC connector suppliers, an evaluation of all the SC connectors that are currently available in the marketplace is impossible.

Attenuator Installation Tips

  • Place the card in the shelf or node.

  • Ensure optics are not powered on.

  • Remove the protective cap from the male side of the attenuator.

  • Clean and insert the attenuator into the OC192 card, and make sure that the attenuator locks in place.

  • Before you remove the protective cap from the female side of the attenuator, gently press in on the back of the protective cap to make sure that the interior portion of the attenuator has locked in place.

  • Do not pull back on the attenuator once you have inserted the attenuator in the card.

  • Clean the fiber jumper to prepare for use.

  • When complete, remove the female protective cap from the attenuator and insert the fiber jumper.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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