Slow download / upload when using a draytek as a Modem
I have an SRX100, was working all good on a leased line, then we moved premises and we only have the option of FTTC. We have 2 issues with this
1) If we connect the SRX to the FTTC Modem (BT Openreach supplied device) then we have loads of sites we cannot browse to, quite intermittent, neve really got to the bottom of this one, so we went with the next option 2) we are connected onto a draytek router with the juniper bridged to it, all sites work as expected, but its slow (line is rated to 80Mbit Down 20Mbit up), we get 5Mbit down 15Mbit Up (the Juniper says its happy with Duplex and all cabling has been replaced with brand new and known good).
I know an old SSG device works perfectly if we configure it like method 1, but thats a private spare that I bought into the office to test with so can't really leave it as the office firewall)
I guess other people may have seen something like this before, I have tried altering MTU around and that doesn;t bring anything to the table speed wise, is there just a general incompatibility with SRX and draytek or SRX and UK FTTC lines in general (tried different ISP as well incase there was something we could change that way, it will be going to the same equipment in the cabinet)