Consider the diagram showing the nodes A$,$ B and C$.$ Link $1$ has a length $7$Km and allows packets to be propagated at a speed of $280$ x $10^6$m$/$sec$,$ while Link $2$ has a length $25$Km and allows packets to be propagated at a speed of $200$ x $10^6$m$/$sec$.$ Link $1$ has transmission rate $25$Mb$/$s and Link $2$ has transmission rate $20$Mb$/$s

A $-----$L$1-----$ B $-----$L$2-----$ C

Node A sends a packet P$1$ of $400$B and then it sends another packet P$2$ immediately after it pushes all bits of P$1$ onto Link $1.$ It takes $498$ us $($micro$-$seconds$)$ for the two packets to arrive at node C$.$ What size is P$2$ in Bytes?