1. RJ45 SFP modules typically consume more power compared to other SFP modules. As a result, they can get warmer.
   
2. RJ45 SFP modules buffer the packets. The buffering causes a small additional delay. Overflowing the buffer can also result in packets being dropped inside the SFP module.
   
1. The additional delay may be visible as an increased gPTP neighbor delay. Certified AVB-Milan devices with RJ45 ports will not become 'asCapable' when the neighbor delay goes above 800ns. Therefore, compensation might be needed as explained below.
3. With RJ45 SFP modules, the interface between the SFP cage and the SFP module (Green arrow) may operate on a different speed than the Ethernet wire speed (Blue arrow). The interface between the SFP module and the SFP cage will run at the native speed of the SFP module. When using AVB-Milan, it is recommended to utilize the SFP module at its maximum speed such that both speeds match.
   

gPTP correction to compensate gPTP neighbor delay

1. LU 90 01118 - 10GBase-T SFP+ Copper Transceiver
   
2. LU 90 01127 - 1000Base-T SFP Copper Transceiver
   

1. Determine the correction necessary
   
1. Typically this can be done by connecting using a very short cable with neglectable delay and observing the gPTP neighbor delay.
   
2. Open an HTTP Rest client such as Postman or the rest-client available on SWITCH_IP_ADDRESS/__rest-client.html
   
3. Use 'PUT' as method
   
4. Use the path /api/gptp/ports/<port number>/correction. In the example below, port number 25 is used.
   
5. Set the payload and fill the correction values you determined. In the example, a correction of 220ns is applied on ingress and egress.
   {"ingress_correction":220,"egress_correction":220}
6. Click the 'send' button.