This is for people wondering about what type of port forwarding to use on office or corprate router, there are three types port fowarding port triggering, externel port forwarding, upnp forwarding. If your confused well the answere is to use Upnp port forwarding on this type of setup. Every router might have these named slightly diffrent and may have few more options but Upnp port forwarding works best, even when not using Upnp setups. good luck!!!!