The CPAK transceiver was the first to use CMOS Photonics, often known as silicon photonics. Complementary metal–oxide–semiconductor (CMOS) is a semiconductor technology that controls the passage of photons rather than electrons. CMOS/Silicon photonics is a technology in which the alignment of two sectors creates some synergy, primarily by utilising massive investments in semiconductor production previously made. What does this mean for networking? There are two primary areas where cpak transceiver has an advantage: first, at the time of launch, it had the lowest 100G footprint, allowing for increased port density and energy efficiency (from 4W to 7.5W per module, according to Cisco marketing materials).
We are approaching the age of 100G optical transceivers, thanks to the rapid expansion of public cloud, Internet of Things (IoT), and artificial intelligence (AI). Cisco’s proprietary 100G optical transceiver module, known as CPAK, was announced in March 2013 and offers a high-density 100Gbps connectivity solution for corporations, service provider data centres, and edge networks. Is the CPAK 100G optical transceiver still relevant today, given the fast advancement of technology in recent years? Let’s take another hard look at it.
What about the rivalry?
cpak transceiver modules were introduced at a time when CFP2 was a little late to market, but today’s 100G application equipment vendors have a wide range of interface modules to choose from, including CFP4 and QSFP28, which both have smaller footprints and lower energy consumption, thus eliminating both of the CPAK module’s unique selling points. True, CFP4 and QSFP28 modules are made with traditional VSCEL laser technology, but photonics suppliers such as Finisar and others are demonstrating silicon photonic based prototypes at the same time.
CPAK is a Cisco switch and router form factor with standard interfaces that may be configured in a variety of ways: 100GBASE-SR10, 100GBASE-ER4L, 100GBASE-LR4, 10x10G-ERL, and 10x10GBASE-LR are protocols that enable 100G connections over various distances and fibre types. For a total data throughput of 100Gbps, it features 10X 10Gbps and 4X 25Gbps modes. Cisco CPAK 100G modules employed CMOS photonics to combine the highest density and bandwidth with the lowest power consumption available on the market until the introduction of QSFP28. You may also look at the density to see if it allows the switches’ performance to run smoothly.
Juniper Networks has announced the availability of a 1TB line card for PTX with CFP2 pluggable optics. The fact that prominent photo electronic manufacturers like Sumitomo, Finisar, JDSU, and Avago have embraced the open source CFP2 standard is, in their perspective, excellent indication of its future potential.
There are open source MSA compatible 100G devices, such as CFP/2/4 and QSFP28, that perform similarly to or better than CPAK. The main concern for networkers should be the open source vs proprietary issue. When new pluggable optical form factors were first introduced, their initial costs were astronomical. However, because the majority of them are MSA Open-Source products, the industry quickly adopts them, and 3rd party optical solution vendors such as ourselves assist the market in driving down pricing and saving huge costs for service providers, operators, and data centres, as optical pluggables account for 15-30% of active equipment CAPEX.
The Use of CMOS Photonics
The main distinguishing characteristic of the CPAK 100G is that it is the world’s first 100G optical module based on CMOS photonics. CMOS photonics, also known as silicon photonics, is a technique that uses many circuit components in a highly efficient design to control the flow of photons instead of electrons, and then prints whole circuits directly on silicon wafers to make optical devices. As a result, the CMOS-based CPAK 100G transceiver has a lower footprint but a greater port density, allowing for exceptionally efficient, low-power optical circuits.
Various Interface Options
CPAK 100G can handle a wide range of distances and fibre types. The distance ranges from 70 metres to 25 kilometres. CPAK may be used with SC/LC connectors and MPO/MTP connectors for connections and cabling. CPAK also offers a high level of compatibility. Different types of 100G modules may generally communicate with each other using the same standard and at the same speed. 100GBASE-LR4 from CFP/CFP2/CFP4 or CPAK 100G, for example, will work together.
Smaller Dimensions and Less Power Consumption
CPAK optical transceivers are 20% smaller and utilise 40% less power than CFP2 modules. In other words, if you utilise CPAK 100G modules in your data centre switches instead of CFP2 modules, you can get 20% more port density and front-panel bandwidth. It is, however, somewhat higher than CFP4 and QSFP28.
What Are The Differences Between Them?
QSFP28 modules are more compact than CPAK modules in terms of form factor. The Cisco CPAK 100GBASE-LR4 module enables links up to 10km via SMF with a nominal power consumption of less than 5.5W, whereas the QSFP28 100GBASE-LR4 module consumes almost 3.5W and supports links up to 10km. When it comes to competing with QSFP28 optical transceivers, CPAK 100G optics have no chance. It is one of the best products that can help the system because of the size that it has.
The CPAK 100G’s Future
The CPAK transceiver, with its proprietary CMOS photonics technology for high port density and front panel bandwidth, is a significant advancement in optical networking. However, in such a fiercely competitive business, predicting which product will be popular for a long period is impossible. After all, technology is the one who makes all the choices. Today, it has been revealed that CPAK is no longer indispensable. QSFP28 transceivers, which have shown fantastic results in constructing 100G networks, have posed the largest hurdle to winning the market thus far. Although the use of CPAK 100G has declined significantly, it remains important for some older equipment.
The technology for 100G transceivers is currently maturing. Because of its tiny size and low power consumption, the CPAK 100G transceiver module is popular. CPAK, on the other hand, cannot compete with open-source 100G devices (CFP/CFP2/CFP4/QSFP28) for 100G high-density connectivity.