CPAK 100G Transceiver – The Challenges It Might Face In 2017

Higher and higher speed networks are the cry of the hour. The top cream players have already outperformed the set standards and are coming with solutions to enable the end users enjoy speed that is needed for flawless cloud and content experience. All these developments have been made possible only by working continuously on increasing the quality and capacity of network components. While the connectors are moving from LC to MTP type, the transceivers are also progressing in sync with the emerging trends. From XENPAK to CPAK, the world of transceivers has seen phenomenal progress and it is continuing to keep the makers on toes owing to the constant increase in expectations of the end users.

So, what CPAK 100G transceiver actually is

CPAK is actually a proprietary form factor of Cisco, but to make the market conditions easier for buyers, many third party vendors have started making CPAK 100G transceiver compatible. This transceiver is advancement over the maiden product of 100G series, i.e. CFP transceivers from Cozlink. It is less costly than the latter too. Compared with CFP transceivers, it has smaller footprint and is energy efficient too.

Main features of CPAK 100G transceiver

CPAK 100G Transceiver

CPAK transceiver has incorporated all the features suggested in IEEE standard modules and is made similar to 100GBASE-SR10, 100GBASE-ER4L, 100GBASE-LR4, 10x10G-ERL, 10x10GBASE-LR, etc. in specifications. The data speed supported is 100Gbps achieved by 10x10Gbps and 25x4Gbps modes. It is compatible with MPO-24 breakout cables and thus, can be used interchangeably with 10GBASE-SR transceiver. Similarly, 10x10G-LR CPAK is compatible with 10GBASE-LR optical modules. CPAK LR4 transceiver is also compatible with CFP modules that were introduced just a few days after the launch of this form factor, which support 100G optical links terminated with SC connectors.

The unique feature of CPAK 100G transceiver is that it utilizes CMOS Photonics technology. This transceiver form factor introduced by Cisco is designed to work with a wide variety of Cisco routers and interfaces such as CRS-X Carrier Routing System; ASR 9000 Series Router; 4000, and 6000 Series Routers; the Nexus 7000 and 7700 Series Switches, NCS 2000, and the Cisco ONS Transport Platform.

CPAK transceiver has 20% smaller footprint than CFP modules. These are more power-efficient as these dissipate 40% less power than CFP transceivers. Thus, the data centers, when updated with a more power-efficient, high speed network are proposed to be run on CPAK transceivers; this is one of the favorable situations that may work for CPAK modules in 2017.

Most important advantage of CPAK 100G transceiver lies in the fact that it delivers exceptionally high port density and front panel bandwidth. Its footprint is still larger than that of CFP4 and QSFP28 optical modules.

Comparing CPAK with QSFP28

To understand whether CPAK will be able to cut the competition in 2017 or not, it is essential to pit it against the star performer of 100G series, i.e. QSFP28 transceiver. So far, the QSFP28 transceiver has delivered fabulous results in terms of developing 100G networks. QSFP28 is the smallest form factor and is surely smaller than CPAK too. CPAK transceiver, like QSFP28 modules, can deliver data connectivity up to a distance of 10km over single mode fiber at power supply of less than 5.5W. Though it is meeting the data connectivity range benchmark but lags behind the QSFP28 modules in power-efficiency, as the latter requires only 3.5W of power to do the same job. Thus, the biggest challenge to win the market in 2017 for CPAK comes from QSFP28 transceivers.

What CPAK transceiver needs to sail through 2017?

CPAK transceiver, as mentioned above, has no chance in front of QSFP28 transceivers that are ruling the market as of now. It would need more and more devices to have CPAK compatible ports so that its relevance can be established in the market. As of now, Cisco and its compatible vendors have designed switches with CPAK ports and this scenario has to be changed as soon as possible to enable this CMOS enabled transceiver stand out amongst other form factors. A small respite to CPAK comes from CFP to CPAK adapter developed by main league makers, so that it can at least be used across CFP supported devices. Another support from CPAK would be coming from third party OEMS like Cozlink that would roll out Cisco CPAK compatible modules to help the users who are looking for replacements for the pricey originals.

Given the fact that 100G modules are placed in lower price range than 40G counterparts, it has become natural for 100G transceiver market to grow more rapidly. To meet the requirements of the market, all the existing form factors supporting 100G, available in the market right now, are going to be mature with better electronics features in coming times. So, CPAK has to maintain a steady speed in terms of development and compatibility to stay in the league of bestsellers of 2017.


With only unique feature of having CMOS Photonics technology, the CPAK has been able to offer something interesting to 100G technology buyers. However, this module is yet in the developing stage and needs to have better electronics to combat the competition posed by QSFP28 modules. The makers are improving the design and functioning of the existing form factors and this spirit has to be maintained by the CPAK developers also, so that power efficiency factor of QSFP28 can be answered by something more powerful and energy-efficient. This is the only key for CPAK to make the mark in fiber optic transceivers 100G market.