Breaking of Frames in Ethernet switch/Mux

Hi All,

I am very new to the Ethernet area.

I am trying to design and Implement an Ethernet switch or Multiplexer.

so say if I am bridging between two 1-gbps channels with one 2-gbps
channel.
when I think of designing a TDM switch between the 2 channels of 1
gbps my basic design will contain a MAC and a FIFO right...?

I was thinking that if the incoming data frame is long so that it will
cross the TDM slot for that channel of 1 gbps. then I will have to
break that frame store the remaining data in fifo and send it in the
next slot.

Here I am not getting is that how it will get reconstructed at the
receiving end .
So firstly is it allowed to break like this if yes then how to insert a
packet number etc in the frame.

Please Help...

Thanks & Regards.
Kedar