It may be that your network is not configured with support for multicast, which is an IP standard put in place over 20 years ago to make this kind of data transfer more efficient and avoid these kinds of problems. IP multicast is not a new technology and support for it has been pretty standard in most switches and routers for many years now, but because Ghost is one of the few major applications to make use of it (although VoIP equipment also makes significant use of multicast, that often gets deployed on separate infrastructure dedicated to telephony).
Very old (or consumer-grade) equipment that does not support multicast may still be around, and when multicast was introduced to TCP/IP it was done in a way which ensured that equipment which did not support it directly would treat the multicast data as if it was broadcast. This was done to ensure that the data could still get through, and so perhaps what your networking guys are seeing are a consequence of this.
The ideal approach would be to ask your network managers to check specifically for the IGMP configuration on their network equipment; if they aren't familiar with IP multicast, they can read
a good introduction to it from Cisco, and they should check the vendor manuals for their equipment for configuration topics related to IGMP, which is the
standard protocol used to manage multicast traffic.
I've written a reasonably large number of articles here on Connect about Ghost's networking over the years which can be found if you know the right search term to use and IGMP is the most important search term.
Note that IGMP is a router protocol, but it can also affect switches (as modern switches behave more like routers and may often BE routers as well). There is a special concept in relation to switched environments which use multicast called IGMP snooping which is discussed in the Cisco manual linked above and which your network folks also need to be aware of.