Old 10mbit standards like 10Base2 (thinnet) and 10Base5 (thicknet) are used in a bus topology, multiple devices are connected to one continous cable (or with BNC T-connectors, but same principle).

Is the same true for the new "single pair ethernet" standards 10Base-T1L and 10Base-T1S? Can these be used in a bus topology as well or do they require a star topology like most other PHYs today?

  • \$\begingroup\$ What does your research indicate? \$\endgroup\$
    – Justme
    Aug 26, 2021 at 15:21
  • \$\begingroup\$ @Justme to be honest, I don't know. I found little information about these standards since they're rather new and not widespread. \$\endgroup\$
    – Zciurus
    Aug 26, 2021 at 20:29
  • \$\begingroup\$ Yes and Yes ...both are bus connections over typically twisted pair wiring.. \$\endgroup\$ Aug 27, 2021 at 2:43
  • \$\begingroup\$ @JackCreasey Hi Jack, thanks for the answer. Can you share your source? \$\endgroup\$
    – Zciurus
    Aug 27, 2021 at 6:26
  • 1
    \$\begingroup\$ 10BASE-T1L cannot be used in a bus network. \$\endgroup\$
    – TimB
    Aug 28, 2021 at 3:35

1 Answer 1


10BASE-T1S can be used in a bus network (mixing segment) with up to at least 8 nodes and up to at least 25m. A Physical Layer Collision Avoidance Algorithm (PLCA) is also used in conjunction with the traditional CSMA/CD medium access control to avoid collisions and allow up to 95% network utilization.

10BASE-T1L supports only point-to-point link segments, but up to 1000m.

Source: IEEE 802.3cg-2019 Clauses 146 (10BASE-T1L), 147 (10BASE-T1S), and 148 (Physical Layer Collision Avoidance).


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