Cabling Options for 40Gbps Parallel Optical Modules

With speeds in the data center now increasing from 10 Gbps to 40 Gbps and eventually to 100 Gbps, different optical technologies and cabling infrastructure are required. The QSFP+ transceiver is the dominant transceiver form factor used for 40 Gigabit Ethernet applications. In 2010 the IEEE standard 802.3ba released several 40-Gbps based solutions, including a 40GBASE-SR4 parallel optics solution for MMF. Since then, several engineered solutions have been released, including 40GBASE-CSR4, which is similar to 40GBASE-SR4 but extends the distance capabilities. This article will mainly introduce the typical cabling components and the cabling options for 40Gbps parallel optical modules.

Typical Cabling Components

MTP trunk cable—These fiber trunk cables are typically 12 to 144 fibers and create the permanent fiber links between patch panels in a structured environment. They are pre-terminated from the manufacturer with MTP connectors at a specified length and have a pulling grip for easy installation. Connector housings — The connector housings are physically mounted in a 19-inch rack or cabinet. They are typically offered in various sizes such as 1 rack unit (1RU), 2RU, or 4RU, which refers to the amount of rack space required for mounting. MTP connector panel — The MTP-MTP connector panel (sometimes called the bulkhead) is installed in the housings. It offers a connection point between the MTP trunk and the MTP jumper for 40- and 100-Gbps applications. The trunk cables plug into the rear of the panel, and the MTP jumpers plug into the front of the panel. LC or MTP jumpers — The LC or MTP jumpers create the connection between the device port and the structured cabling through the connector panel. For instance, Fiberstore provides Push-Pull LC cable which utilizes a flexible “pull-tab” allowing for the connector to be disengaged easily from densely loaded panels without the need for special tools.

Cabling Options for 40-Gbps Parallel Optical Modules

In 2010 IEEE 802.3ba approved the 40GBASE-SR4 physical-medium-dependent (PMD) multimode parallel optic solution, which uses eight fibers to transmit four duplex channels each at 10 Gigabit Ethernet. Each transceiver transmits over four fibers and also receives transmissions over four fibers.

Also as previously mentioned, parallel optics does require a change from traditional cabling methods, which requires learning and so creates an incentive to move to the bidirectional solution at 40 Gigabit Ethernet. The main advantage of the parallel optics transceiver over the bidirectional transceiver at 40 Gigabit Ethernet is reach. For example, if you cable your data center with OM3 fiber at 10 Gigabit Ethernet, you can support distances up to 300m. Then if you move to 40 Gigabit Ethernet, you can support the same 300m distance with the same OM3 fiber and a 40GBASE-CSR4 transceiver.

Connectivity Options

Apart from the fiber optic cabling connectivity options for 40G optical modules, there are also some other alternatives to support the 40G network systems. The table below gives you a comprehensive list of these connectivity options and compare them in view of their applications as well.

Fiberstore offers a wide range of 40G cabling assemblies, such as MTP-LC, MTP-ST, MTP-FC, MTP-MU, etc. Besides, we can also customize according to your special needs. All fiber counts are available in plenum, riser, or outdoor ratings to suit different kinds of environment. Our high quality factory pre-termination eliminates the need for costly field termination and testing.