Overview… 40/100G CAUI testing

 

Ethernet at speeds of 40 and 100 Gbps uses the CAUI standard at Layer-1, the physical coding sub-layer. This divides the traffic into a number of physical lanes, which are transmitted together in various combinations depending on the interface type.

 

Within each lane the data is divided into 66-bit codewords which contain a 2-bit header. The data in each physical lane carries an alignment marker which contains the virtual lane number for this portion of the traffic. 

 

Lanes may be physically swapped along the path from transmitter to receiver, and once the alignment markers are located inside each received lane the virtual lane numbers are used to put things in the right order.

 

The lanes may also get skewed in time relative to each other during transit, and the alignment markers are also used to do the required de-skewing in the receiver.

 

 

On the transmit side, you can manually swap and skew the lanes:

 

Xena cauitxlane CAUI testing

 

You can also inject different kinds of CAUI errors into specific lanes.

 

 

On the receive side, you can see whether there is proper header lock and alignment lock, and which virtual lane and actual skew is detected for each physical lane:

 

Xena cauirxlane CAUI testing

 

You can also see which kind of CAUI errors are detected in each lane.

 

40/100G configuration

40/100G PRBS testing

 

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CAUI testing