Dmitry Yemanov wrote a series of articles related to Firebird network
performance
First article is : Generic thoughts about the network performance
http://dyemanov.blogspot.com/2012/01/generic-thoughts-about-network.html
Second article is : Protocol packets and buffers
http://dyemanov.blogspot.com/2012/03/protocol-packets-and-buffers.html
And the last one is : Records batching
http://dyemanov.blogspot.com/2012/03/records-batching.html