If you don't configure any limits, and there are no restrictions on the AudioCodes, you can use all 4 ports for incoming or outgoing. However, you will of course be unable to place outgoing calls if all 4 ports are in use for inbound, and vice versa.
If you want to dedicate ports for inbound/outbound, you can do this on Speech Server by setting MaxIncomingCalls and MaxOutgoingCalls. You might be able to do something similar on the AudioCodes, you would have to look at it's documentation. Given a single gateway & single Speech Server (i.e. what you have with just a 4 port board), it doesn't really matter whether you limit the #incoming at the gateway or Speech Server, however you will get better behaviour if you limit #outgoing at Speech Server rather than at the gateway. If you were in a larger-port situation, sharing a single gateway across multiple Speech Servers, then you would get better system-wide control by applying the limits at the gateway.
