Optics Telecom

Quad small form-factor pluggable plus (QSFP+) direct attach copper (DAC) cables are cables with QSFP+ module at one end or both ends. They are suitable for in-rack connections between QSFP+ ports of EX Series switches. They are suitable for short distances of up to 10 meters, making them ideal for highly cost-effective networking connectivity within a rack and between adjacent racks. This article will introduce EX Series switches and QSFP+ DAC for EX Series switches.

EX Series switches deliver scalable port densities and carrier-proven high availability features that consolidate legacy switch layers, helping to reduce capital and operational expenses and advance the economics of networking. For example, the EX 4200 series Ethernet switches with Virtual-Chassis technology, deliver the same Gigabit Ethernet (GbE) and 10GbE port densities as traditional chassis-based switches, but at one-eighth the footprint and less than one third the cost. The EX Series switches are right-sized for campus, data center and remote office environments and feature many of the same carrier-class hardware and software architectures found in core routers that were purpose-built to support the convergence of data, voice, and video onto a single always-on network.

By alleviating the cost, complexity and risk associated with legacy switch infrastructures, the EX Series switches enable high-performance businesses to deploy a high-performance network infrastructure based on three key tenets – operational simplicity, carrier-class reliability, and integration and consolidation – to enable ubiquitous access to strategic assets, reduce network downtime and enhance overall security to shared assets across the extended enterprise.

QSFP+ direct attach copper (DAC) cable is hot-removable and hot-insertable. QSFP+ DAC mainly has two kinds. One is a cable that connects directly into two QSFP+ modules, one at each end of the cable. The cables use integrated duplex serial data links for bidirectional communication and are designed for data rates up to 40 Gbps. The other is a breakout cable consisting of a QSFP+ transceiver on one end and four SFP+ transceivers on the other end. The QSFP+ transceiver connects directly into the QSFP+ access port on the QFX Series device. The cables use high-performance integrated duplex serial data links for bidirectional communication on four links simultaneously. The SFP+ links are designed for data rates up to 10 Gbps each.

The following table describes the software support for QSFP+ passive DAC cable lengths on EX Series switches for Junos OS releases.