FIX Test Servers

Imported from previous forum

I work for Thomson Financial Software Solutions and am running a project to implement FIX into our Buy-side Order Management System called OpenTrader.

I’m wondering if there are any ECNs or networks out there that have test FIX servers that they would allow us to connect to.

We’ve implemented FIX 4.1, 4.0 and 3.0 and we’re looking for sell-side brokers to test these different versions on.

Is anyone aware of any fully-functional sell-side simulators on the market.