The ports look OK. I suppose you have taken into account there are actually 3 (or 4) nodes with network paths between then to care for - source machine, converter server, destination ESX server, and eventually destination vCenter Server. (e.g. port 902 is not used between source and converter)
Can you try to manually install the agent on the source? This is the easiest workaround. If that's not an option, pls upload the worker log for further examination.
Regards,
Plamen