Trunk config - help needed!

Hi all - newbie here - I have setup VitalPBX OK and all working. I have sucessfully setup a user/password trunk (VOIP Unlimited) with inbound and outbound calls all working. I am now trying to setup a trunk from another provider(Nexbridge) which is IP based and have no idea what settings to put where. Details provided are:

Outbound Host(primary/backup) - 2 IP addresses
Inbound Host (load balanced) - 2 IP addresses
DTMF mode - RFC 2833

I have tried to understand the setting from various examples on the web but with no sucess.

Can anybody help?

I have finally managed to get both trunks working. If anyone needs help with these config please message me.