About the Cisco Nexus 3550-H Hydra


The Cisco Nexus 3550-H Hydra (formerly ExaLINK Hydra) is the world’s highest density Layer 1 switch. Unlike traditional network switches that operate at the data-link layer (layer 2), the Nexus 3550-H operates at the physical network layer (layer 1). Connections through the device are made electrically through a matrix switch. This allows the device to tap into connections (for network monitoring), patch connections between ports (for reconfiguration) and fan-out connections from one port to many (for high speed applications), at nearly zero latency (<5ns).

Render of the Nexus 3550-H

The Cisco Nexus 3550-H Hydra L1-160

The Nexus 3550-H is orderable as a Cisco Nexus 3550-H Hydra L1-160 (formerly Hydra 160) (shown above) with 20x QSFP-DD connectors, or a Cisco Nexus 3550-H Hydra L1-144 (formerly Hydra 144) with 36x QSFP connectors.

Overview of features

  • Tap, patch and replicate
    Tapping with the Nexus 3550-H is far more flexible than using traditional optical taps, and does not suffer from signal degradation associated with high-fanout tapping. Patching allows the Nexus 3550-H to dynamically reconfigure the physical topology of your network with very low latency overhead. Both patching and tapping/replication is done at port to port latencies of 3-7ns. Taps through the Nexus 3550-H employ active signal regeneration so that tapping is near transparent to other devices in your network.
  • Packet aware statistics and monitoring
    Although the Nexus 3550-H operates at the physical layer, it is fully packet aware. Every port on the Nexus 3550-H is monitored for vital packet statistics including the number of packets/bytes transmitted/received, and transmit/receive errors. The device also provides deep diagnostics on each of its 20 QSFP-DD ports including light levels, operating temperatures, transceiver capabilities, and more. All of these statistics are available at no latency cost on the critical path.
  • Enterprise management platform
    Enterprise manageability features are core to the Nexus 3550-H. The Nexus 3550-H features an all new management platform based on the reliable and highly successful Cisco Nexus 3550-F Fusion (formerly ExaLINK Fusion) product series. The Nexus 3550-H features a powerful x86 based management CPU, dual (1G & 10G) Ethernet management interfaces, USB and RS232 based console access, and 10Gbps access from the management CPU to the dataplane.

QSFP-DD connectors

The Nexus 3550-H L1-160 is the world’s first networking device to use double density QSFP connectors (QSFP-DD). QSFP-DD connectors are 100% backwards compatible with legacy QSFP connectors, enabling a smooth transition path from legacy network cabling/connectors to these high density connectors. The Nexus 3550-H works with all brands of QSFP-DD modules and is not tied to a particular brand.

Other features

  • Dedicated RJ45 and SFP+ management ports (1G/10G)
  • Robust and intuitive command line interface (CLI), available over serial, SSH and telnet.
  • Software updates via USB, TFTP, console or web interface
  • Monitoring of available QSFP-DD parameters, including QSFP-DD model information and dynamic parameters such as received power, transmitted power and temperature
  • Log access via CLI and remote logging via syslog
  • TACACS+ and multi user support
  • Time sync via PPS, GPS, PTP & NTP (coming soon)
  • Redundant, hot-swappable power supplies

This page was last updated on Feb-18-2021.