p all 2 all test, only fat pipe switch is used concurrently

$ simdag/network/mxn/test_intra_all2all ${srcdir:=.}/simdag/network/mxn/platform_4p_1switch.xml --cfg=path:${srcdir} --log=sd_kernel.thres=warning "--log=root.fmt:[%10.6r]%e(%i:%P@%h)%e%m%n"
> [  0.000000] (0:@) surf_workstation_model_init_ptask_L07
> 8