Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

ethtool says that "Supported ports: [ TP MII ]" and "Port: MII". I guess that TP means twisted pair and Media Independent Interface. However physically I see that network card uses twisted pair cable, not this MII connector. So how can it be explained?

share|improve this question

1 Answer 1

up vote 10 down vote accepted

All modern Ethernet chips have the MAC built-in, and use a MII protocol over GMII, RGMII, or SerDes physical ports to communicate with the PHY device (even if it's built-in, this is usually true). If it's going to be a twisted pair interface, from the PHY the signal passes through a set of transformers and into the RJ-45 connection.

+-------+   +-------+   +-------+       +-------+    +-------+   +-------+
|       |   |       |   |       |       |       |    |       |   |       |
|Host   |<--+       |<--+       |<------+       |<---+       |<--+       |
|Ctrl   |   | FIFOs |   |  MAC  |  MII  |  PHY  |    |Xformer|   | RJ-45 |
|uC     +-->|       +-->|       +------>|       +--->|       +-->|       |
|       |   |       |   |       |       |       |    |       |   |       |
+-------+   +-------+   +-------+       +-------+    +-------+   +-------+
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.