We have several forefront tmg servers connected to a 100mbit v-ethernet fibre connection from our ISP. Download speeds are always good (25-50mbit), but for some reason, upload speeds from computers behind the TMG firewalls are always much slower (1-5mbit).
The setup is pretty simple - a cisco router manages the connection and is connected to an unmanaged gibabit switch. The TMG servers also have their external interfaces connected to that switch. If I plug a notebook into this switch (assigning a public address and bypassing TMG) I get the upload speeds I would expect.
I've tried manually setting connection speeds, duplex, etc, on the TMG external nics but it hasn't made a difference.
Also, the tmg servers are from diferent vendors / network cards and all exhibit the same symptom, so it seems like it must be something within TMG.
Any thoughts would be greatly appreciated.