Introduction to HPE 40G Optics

Recently the increasing network infrastructures are upgrading to 40GbE to ensure better performance, which greatly promote the popularity of 40G optical devices, especially the 40G optical transceivers and 40G QSFP+ cables. 40G optics, featured by its unique specification, are designed to meet different connectivity applications in data center. Telecom vendors like HPE, Cisco, Juniper, Arista are offering all types of 40G optics to meet the market needs, of which 40G optics form HPE are the commonly used products on the market. This article will have a short introduction to the HPE 40G modules and DAC cables.

Shedding Light on HPE 40G QSFP+ Modules

The 40G QSFP+ module is a compact, hot-pluggable transceiver used for data communications applications. It supports Serial Attached SCSI, 40G Ethernet, QDR (40G) and FDR (56G) Infiniband and other communications standards. Compared with SFP+ modules, QSFP+ transceiver increases the port-density of 3-4 times. The following part will mainly introduce three different types—40G LR4 QSFP+ transceiver, 40G SR4 QSFP+ transceiver and 40G CSR4 QSFP+ transceiver. Figure 1 shows a QSFP+ modules plugging into a HPE switch.

• HP 40GBASE-LR4 QSFP+ Transceiver

The 40G LR4 QSFP+ transceiver enables high-speed 4x10G operations and can be interoperability with 10GBASE-LR interfaces. Together with the LC connector, it can support an optical link length up to 10 kilometers over single-mode fiber. 40G QSFP+ cable is compliant with QSFP+ MSA and IEEE 802.3ba. In order to realize the function of transmitting 4-channel signals over single-mode fiber, this transceiver has to introduce MUX/DEMUX to multiplex/de-multiplex optical signals.

• HP 40GBASE-SR4 QSFP+ Transceiver

The 40G SR4 QSFP+ transceiver compatible with the 802.3ba 40GBASE-SR4 standard, provides a 40G optical connection using MPO/MTP fiber ribbon connectors. Unlike the 40G LR4 QSFP+ transceiver, this transceiver are used together with multimode fiber, supporting with a link length up to 100 meters on OM3 cable and 150 meters on OM4 cable. Take HPE JG325B as an example, it supports link lengths of 100m and 150m, respectively on OM3 and OM4 multimode fiber at a wavelength of 850nm. It primarily enables high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber connectors and can also be used in a 4x10G module for interoperability with 10GBASE-SR interfaces.

• HP 40GBASE-CSR4 QSFP+ Transceiver

40GBASE-CSR4 QSFP extends the reach of IEEE 40GBASE-SR4 interface to 300 and 400 meters on laser-optimized OM3 and OM4 multimode parallel fiber, respectively. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber parallel cables with MPO/MTP female connectors or in a 4x10G mode with parallel to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces.

Features of 40G HP QSFP+ Modules

• Hot-pluggable input/output device that plugs into a 40 Gigabit Ethernet QSFP port
• High-speed electrical interface compliant to the IEEE 802.3ba standard
• Certified and tested on QSFP 40G ports for superior performance, quality, and reliability
• Digital Diagnostics Monitoring Interface

In addition, QSFP+ modules provide 40Gb/s Ethernet data rates over MMF optic cable and SMF optic cable. QSFP+ modules taking up very little space on a switch or server interface, allowing vendors to provide multiple QSFP+ ports in the same space. Besides the QSFP+ transceivers, HPE also offers QSFP+ cables for interconnection, which will be introduced in the next part.

HP 40GbE QSFP+ Cables

HPE offers a variety of 40GbE optical devices, such as QSFP to Four SFP+ copper breakout cables, QSFP to Four SFP+ active optical breakout cables, QSFP to QSFP active optical cables, etc. Each has its unique characteristics. Take HPE QSFP+ breakout cable as an example, compatible HPE JG330A (QSFP+ to 4SFP+ Passive Copper Cable) is very suitable for short distances and offer a very cost-effective way to establish a 40-gigabit link between QSFP port and SFP+ port of HPE switches within racks and across adjacent racks.

HPE QSFP+ to QSFP+ active optical cables are suitable for 40G Ethernet. And there are two common active optical cables available on the market—QSFP to 4 SFP+ breakout AOC and QSFP to QSFP AOC (see in the above image). QSFP to 4 SFP+ breakout AOC is a 4×10 Gb/s parallel active optical cable that transmits four separate streams of 10 Gb/s data over ribbon cables in a point-to-multipoint configuration. This cable contains a QSFP+ module on one end and four separate SFP+ modules at the other ends. The latter is a 40 Gb/s parallel active optical cable which transmits error-free parallel 4×10 Gb/s data over multimode fiber (MMF) ribbon cables.

Choose Compatible HPE Transceiver Modules

The first factor that forces people to choose third-party transceiver modules other than original modules is budget. Because the price of the original products is usually three or four times higher than 3-rd party devices. Designers can’t afford it. In addition, the third-party transceiver modules offered by reliable vendors are guaranteed to be well-tested and fully compatible with the major brand. It is feasible to buy compatible HPE transceivers from reliable OEM vendors. For example, FS.COM is devoted to design, manufacture, and sell a broad portfolio of optical products, including compatible HPE 40G QSFP+ transceivers. We supply high quality QSFP+ transceivers which are used primarily in switches, routers, and data center equipment.