You didn't say what version of Firebird you are using. If it is not
3.x, you can expect very bad performance transferring data over WAN.
FB 3 implemented changes in the wire protocol making things much
faster in high latency networks. The only remaining "problem" is if
you need to transfer blobs (it will be slow).

For more info:
https://www.firebirdnews.org/firebird-3-protocol-benchmark/

[]s
Carlos
http://www.firebirdnews.org/migration-guide-to-firebird-3/

nycfs> I was able to verify that NoNaggle appears to be marking the
nycfs> packets as push to avoid the Nagle Algorithm delays. The
nycfs> packets show up with push flag set from client and server.

nycfs> I am still very disappointed with the performance of the FB clients.
nycfs>

nycfs> An application that normally takes 25 seconds to open on LAN
nycfs> is taking 6 minutes to load on WAN.
nycfs>

nycfs> The actual data transferred is less than 11 Mbit.

nycfs>

nycfs> The bandwidth is not an issue, 100Mbps/100Mbps up/down.
nycfs>

nycfs> Point to Point Bandwidth tests show 95 Mbps with 7.6 ms round trip.

nycfs>

nycfs> Ping tests show client to server ping with 65500 bytes round trip time 19ms.
nycfs>

nycfs> Am I missing something here or what is slowing down these firebird communications???
nycfs>

nycfs> Any help would be appreciated.

nycfs>