Arista CAB-Q-Q-2M-Arista | 40G QSFP+ Passive DAC Cable, 2m Twinax

Q: What equipment is this cable compatible with?
A: The CAB-Q-Q-2M is designed for Arista switches with 40G QSFP+ ports, including the 7000 series platforms. It connects two QSFP+ ports for direct switch-to-switch or switch-to-server connectivity in data centre environments.

Q: What is the difference between passive DAC and active optical cables?
A: Passive DAC cables like the CAB-Q-Q-2M use copper twinax construction and require no external power, making them cost-effective for distances up to 3-5 meters. They consume less power than active optical cables and are ideal for in-rack or adjacent-rack connections.

Q: Can this cable be used for breakout connections?
A: No, the CAB-Q-Q-2M is a QSFP+ to QSFP+ direct cable providing a single 40G connection. For breakout applications splitting 40G into 4x10G connections, you would need the CAB-Q-S series cables instead.

Q: Does this cable work with 100G QSFP28 ports?
A: While physically compatible, this 40G QSFP+ cable is designed for 40GBASE-CR4 applications. For 100G connections, you should use dedicated 100G QSFP28 cables to ensure proper performance and compatibility.

Q: What are the advantages over using optical transceivers?
A: Passive DAC cables offer significantly lower cost, reduced power consumption (no transceivers needed), lower latency, and simplified deployment for short-distance connections. They're ideal for top-of-rack switching and in-row connectivity within data centres.