10GbE on 1GbE network

[Altera_Forum]

Hi all, 

 Maybe its a beginner question .. :)  Can we use a 10GbE board (with 10GbE UDP/IP core) in order to receive UDP packets at 200Mbps rate from an external network ? i mean, is there any problem with the two rates ?  Thanks Shalom

[Altera_Forum]

The core needs to be multispeed and also handle 1GbE. The PHY chip will automatically synchronize to the highest speed achievable by the two partners (1Gb/s) so the core must be able to communicate with the PHY at that speed.

[Altera_Forum]

Ok. Thanks for the answer 

 Always for the same situation(network provide 200Mbps to board) In order to have minimum latency on the channel datapath, should we use 1GbE or 10GbE on board?  Shalom

[Altera_Forum]

10GbE will have a slightly lower latency, because the serialization/deserialization will take less time, but I don't if it will have any significant impact on the whole latency.

[Altera_Forum]

Sorry for the beginner questions.. 

 But if we use 10GbE on the board, should we use any converter to the 1GbE external network ? if yes, so the latency will increase, no?  Shalom

[Altera_Forum]

No, you will only gain some latency if both ends are at 10GbE. If your network is 1GbE anyway, you won't gain anything with a 10GbE board. A converter would only add more latency.

[Altera_Forum]

Yes our network is 1GbE anyway. 

So, have you any idea about the approximate latency of this type of converter( 1GbE to 10GbE and 10GbE to 1GbE) ?  Shalom

[Altera_Forum]

It depends on the converter, I guess. But if you really want to have a latency as low as possible, you should stick to 1GbE everywhere.

[Altera_Forum]

Ok. 

 Thanks for your excellent help  Shalom

[Altera_Forum]

--- Quote Start ---  The core needs to be multispeed and also handle 1GbE. The PHY chip will automatically synchronize to the highest speed achievable by the two partners (1Gb/s) so the core must be able to communicate with the PHY at that speed.  --- Quote End ---    In that case, can the Altera(Startix 4) transceiver in XAUI mode be a good PHY ? I understand that on XAUI mode it cannot work less than 3.175Gbps. right ?  Shalom

[Altera_Forum]

You don't need the XAUI mode. The Stratix IV transceivers can do GbE too.

[Altera_Forum]

ok thank you 

 I need few days to design our system I hope we will be able to continue this discussion  Shalom