Enabling an "Active" plus "Smart" approach to higher-bandwidth Switch-to-Server Ethernet interconnects and Switch-to-NIC bandwidth utilization

Switch to Server Configurations

Requirements & Challenges

  • At 50 Gbps/lane, passive DAC cables barely meet the 3-meter reach requirement, while experts predict 2-meters may be the practical limit for DACs at 100 Gbps/lane.
  • At a typical 26 AWG and 16 twinax pairs per cable, DACs are too rigid, heavy, and bulky, especially when using one ToR for a grouping of 2-3 racks, which restrict airflow and make servicing the rack practically impossible.
  • Rate mismatch between NIC (25 or 50 Gbps/lane) and switch (50 or 100 Gbps/lane) leads to wasted switch bandwidth.
  • Switch PCB consumes too much of the overall 35-dB end-to-end channel budget, greatly limiting cable reach and increasing diameter.
  • DACs and general-purpose Active Electrical Cables (AECs) lack advanced cable and fleet management features essential managing data center infrastructure.

Taurus Smart Cable Module™ (Taurus SCM™) Benefits

  • Smart Electrical Cables enabled by Taurus Smart Cable Modules™ provide a thin, flexible cable gauge, higher reliability, and lower-power profiles to meet 3-meter reach requirement — with a side benefit of relaxing the channel design requirements of the switch PCB.
  • SECs with Taurus SCMs provide gearboxing capabilities to resolve rate mismatch between NICs and Switches with 50G-to-100G PAM4 & 25G-NRZ-to-50G-PAM4 Aggregation and Disaggregation.
  • Taurus SCMs offer system-wide visibility and management features that enable enhanced security, quick debug, and flexible firmware upgrade.
  • Taurus SCMs enable a flexible supply chain by qualifying with leading cable assembly suppliers to support multi-sourced cable solutions with a common set of fleet management features.
Similar Applications


Orderable Part NumberDescriptionMax Data GenCable Line RateModePackage / ConnectorOrdering
EM400-QDX400G QSFP-DD Taurus Smart Cable Module400G50G/Lane, 100G/LanePAM4QSFP-DDContact Us, https://www.asteralabs.com/product-details/em400-qdx/
EM400-EPS400G OSFP Taurus Smart Cable Module400G50G/Lane, 100G/LanePAM4OSFPContact Us, https://www.asteralabs.com/product-details/em400-eps/
EM800-EPS800G OSFP Taurus Smart Cable Module800G100G/LanePAM4OSFPContact Us, https://www.asteralabs.com/product-details/em800-eps/
EM800-QDX800G QSFP-DD Taurus Smart Cable Module800G100G/LanePAM4QSFP-DDContact Us, https://www.asteralabs.com/product-details/em800-qdx/
EM200-QDX200G QSFP-DD Taurus Smart Cable Module200G25G/LaneNRZQSFP-DDContact Us, https://www.asteralabs.com/product-details/em200-qdx/