p latency check, 2 x 1 byte, same direction, shared link

$ simdag/network/p2p/test_latency2 ${srcdir:=.}/simdag/network/p2p/platform_2p_1sl.xml --surf-path=${srcdir} --log=sd_kernel.thres=warning
> [0.000000] [surf_workstation/INFO] surf_workstation_model_init_ptask_L07
> 2.5

p latency check, 2 x 1 byte, same direction, fat pipe

$ simdag/network/p2p/test_latency2 ${srcdir:=.}/simdag/network/p2p/platform_2p_1fl.xml --surf-path=${srcdir} --log=sd_kernel.thres=warning
> [0.000000] [surf_workstation/INFO] surf_workstation_model_init_ptask_L07
> 1.5

p latency check, 2 x 1 byte, same direction, link - switch - link 

$ simdag/network/p2p/test_latency2 ${srcdir:=.}/simdag/network/p2p/platform_2p_1switch.xml --surf-path=${srcdir} --log=sd_kernel.thres=warning
> [0.000000] [surf_workstation/INFO] surf_workstation_model_init_ptask_L07
> 4