Huge lags on the client

Hi, sometimes huge lags happen on the client. We are trying to investigate the issue. Sometimes our Photon server sends a packet and a client receives it in more than 1 second. Usually round trip time between the server and the client is 200 ms. So we would like understand a packet is in the client's incoming queue or the server's outgoing queue. Do we have a way to do it? The server is Windows Server 2012 R2 x64 (4.0.29.11263). The client is Windows 7 and it uses Photon Unity SDK (4.1.1.2).