Ethernet has been developed for more than 40 years, as its name “ETHER”, it already reaches the level that pathfinder originally thought to achieve. "Ethernet is everywhere", and it has become the ubiquitous medium of the human information society. In recent years, with the rapid development of the Internet, cloud computing and big data, the construction of the IT infrastructure data centers has been accelerated, a new round of Ethernet upgrades in the data center is also underway, 25G Ethernet is high favored among them.

Data centers’ demand for Ethernet comes from two important considerations, one is energy saving and the other is cost. The fields related to  development of data centers include development of "cloud" and the Leaf/Spine matrix network architecture. With the further improvement of server performance, and the upgrade to 100Gbps from leaf to spine layer connections in data centers, then the upgrade of the server from the existing 10Gbps to 25Gbps/50Gbps is already very meaningful. 10G Ethernet rate standard always could not meet the requirements in the market, and 100G is too expensive, so 25G and 50G Ethernet standards just make up for the shortcomings of the two. In addition, 25Gbps and 50Gbps per channel technology will be the basis of future 100Gbps (4 25Gbps) and 400Gbps (8 50Gbps) Ethernet standards, the optical industry generally hopes to use 25G transmission rate to replace the existing 10Gbps rate.

Introduction of 25GE technical advantages

Compared with 40GE, 25GE technology has one channel cost advantage. For 40G, it uses 10G technology, so need more multiple physical channels. For 25G Ethernet, the key advantage is that many components have already been developed. 100G Ethernet standard four 25Gbps, the components applied the two technologies can be mass-produced, thereby pushing down prices. Through Quad Small Form-factor Pluggable (QSFP), 100G can be split into four 25G, 40G can also be split into four 10G, so multi-rate Ethernet products can be developed and applied.

Use the same low-cost copper cable to obtain faster performance and higher base, the specification stipulates: By using a single switch/NIC SerDes channel, the bandwidth provided by the 25 Gigabit Ethernet link is equivalent to 2.5 times bandwidth of 2 pairs The 10Gbps link of the twin-axial copper cable SFP+ direct-attached copper cable (DAC). By using two switch/NIC SerDes channels running at 25Gbps, a 50 Gigabit Ethernet link can provide 25% more bandwidth than a 40 Gigabit Ethernet link. In addition, compared with QSFP+DAC application, only half the number (4) of twin-axial copper cables are used in the specification. When each channel rate is 25Gbps, the speed of the switch and the NIC chip will run faster, and the power consumption will only increase slightly. However, after the bandwidth is standardized, the advantages in cost and power consumption will be more obvious.

 Compared with 40GE, 25GE Ethernet server is connected to 25GE TOR switch, 25GE can support higher server density in the rack.

For "port density", compared to 10 Gigabit and 40 Gigabit Ethernet connection, 25 Gigabit and 50 Gigabit Ethernet links defined by the "25 Gigabit Ethernet Alliance" specification enable serializer/SerDes channel and twin-axial copper cable performance increase by 2.5 times. Such performance could save more than 50% of rack-level interconnection costs per unit bandwidth, and significantly improve the profit and loss level of MSDC operators. In addition, the implementation of the specification can also broaden the network scale (usually referred to as “base”), and compared to 40 Gigabit Ethernet servers to TOR connections, it can support a higher server density in the rack.

Coptolink can provide a complete product line for data centers 25GE and 100GE Ethernet interconnection applications. According to actual application scenarios, Coptolink provides different solution combinations according to actual application scenarios, customers get great convenience to choose solutions from Coptolink. Below is product line for your reference.

100G Uplink Interconnection + 25G Access Solution