Many data center operators choose MMF or SMF transceivers and fiber, over DACs and AOCs, because they want to simplify and future-proof the cable infrastructure (see Figure 4). Data center TOR and EOR network architectures

The 25G links are implemented with copper Direct-Attach Cables (DAC), Active Optical Cables (AOC) or transceivers, and Single-Mode Fiber (SMF) or Multi-Mode Fiber (MMF). The distance from the switches to a server or NIC generally ranges from half a meter to 100 meters. Next generation data center architectures are generally implemented in either Top-of-Rack (TOR), Middle-of-Row (MOR), or End-of-Row (EOR) configurations, with 25G between the switches and the servers and NICs (see Figure 3).

Cisco transceiver modules for data center applications To meet these needs, data center (Figure 1) operators are now turning to mature, cost-effective 25G Ethernet technology, including new 25G switches and high-bandwidth servers with 25G Network Interface Cards (NIC).Ĭisco’s newest transceivers, including SFP-25G-SR-S, SFP-10/25G- CSR-S, and SFP-10/25G-LR-S (Figure 2) are enabling optical 25G transmission in data centers. Driven by increases in social networking, data and video content delivery, along with demanding business applications, are now pushing beyond the speed limits of traditional server and switch infrastructure. With exponential growth in Internet users and applications, data center traffic continues to experience explosive growth. Written by Craig Pasek, Product Manager, Transceiver Modules Group, Cisco

10g tor switches