IN Brief:
- The Velocity 4902 provides 72 QSFP28 ports and breakout options for up to 288 connections.
- The Velocity 4906 provides 288 SFP28 ports and supports connections up to 25 Gbps.
- Both models support transparent Layer 1 connections and software-configured test topologies.
Keysight Technologies has introduced the Velocity 4900 series of Layer 1 automation switches, allowing network test laboratories to configure physical connections through software rather than repeatedly moving cables between instruments and devices. The series comprises two models covering Ethernet speeds up to 100 Gbps, with remotely managed switching intended to connect laboratory infrastructure to automated development and validation workflows.
The 4902 supports Ethernet speeds from 100 Mbps to 100 Gbps through 72 QSFP28 ports, with breakout configurations allowing up to 288 connections. The 4906 provides a separate configuration with 288 SFP28 ports supporting 100 Mbps to 25 Gbps, trading maximum link rate for more independently configurable connections in the same laboratory automation family.
Both models use a transparent Layer 1 switching matrix, which operates at the physical connection level without performing the conventional packet forwarding functions of an Ethernet network switch. A normal switch examines traffic information to determine where packets should be forwarded, introducing switching behaviour that can influence a test environment. Layer 1 switching instead creates a physical connection between selected ports while leaving attached equipment responsible for generating, receiving and interpreting network traffic.
That distinction allows the automation switch to connect devices under test with traffic generators, analysers and other laboratory equipment without imposing a separate packet processing stage on the measurement path. Keysight specifies low, deterministic latency and support for different physical media, including single-mode and multimode optical fibre, direct-attach copper and active optical cables. Port speed and media settings can be configured individually, accommodating laboratories containing equipment with different interface requirements.
In addition to switching individual physical links, the matrix allows traffic tapping for diagnostics and one-to-many replication. A tapped connection allows traffic on a selected path to be observed by monitoring equipment, while replication can distribute the same generated traffic towards multiple destinations where the test arrangement requires it. These capabilities provide ways to reuse expensive test instruments and observe network behaviour without manually rebuilding laboratory topology each time a measurement changes.
Keysight’s Velocity software can save a laboratory’s physical connection topology, restore it for later test runs and redirect instruments between selected devices under test. Reusing a defined connection map reduces manual cable handling and helps preserve consistent conditions across repeated measurement sequences.
With compatible management and access controls, engineers can allocate shared instruments to remote test configurations as project needs change. Instruments that would otherwise be assigned to individual projects can be connected to different devices under test as requirements change. The switching system does not eliminate physical limits on the number of available ports, compatible interfaces or instruments. Resource reservation and scheduling remain necessary when several teams need access to the same equipment.
Resource reservation and orchestration software in the wider Velocity portfolio can coordinate the physical switch configuration with automated test sequences. Integrating physical connectivity with these software layers allows a continuous integration and continuous delivery pipeline to request laboratory configuration, run validation procedures and release equipment afterwards. The automation system must still coordinate instrument states, software versions and the test results recorded during execution if successive runs are to remain comparable.
As network designs incorporate higher data rates and increasingly complex configurations, physical test environments must accommodate changes in the number and arrangement of connections. A laboratory investigating a 100 Gbps interface has different media requirements from one validating large numbers of 25 Gbps links. The distinction between the two Velocity models reflects those requirements, and suitability depends on simultaneous connections, cable types and available rack space as well as maximum signalling speed.
A two rack unit 4902 configuration suits installations prioritising higher speed QSFP28 links, whereas the 4906 provides more SFP28 connections in six rack units. The appropriate choice therefore depends on whether a facility prioritises high speed QSFP28 interfaces or a larger number of SFP28 connections. Neither model replaces the traffic generation and measurement instruments required for performance testing; the switches provide configurable physical paths connecting those instruments to equipment under examination.
Keysight is accepting orders for both models, with initial deliveries expected in January 2027. The time saved and equipment utilisation achieved will depend on the number of connection changes, the laboratory’s existing automation and access to shared instruments. The switches establish a hardware option for connecting network infrastructure to repeatable, software managed validation processes.
