Harrypatel11 first of all welcome to FreePBX Community Forums, then please consider that you’re asking help about a system that is EOL End Of Life…or, better, definitely abandoned (read just the first post here, not the all thread).
Do yourself a favour and help us to help you efficently: if you’re new to VoIP systems and IP-PBX world consider to start with an IP-PBX system that is actively developed, often updated, community and commercially supported, open, with modular features and with a strong community of users and developers just behind.
That’s not Trixbox CE (read also here).
Also, keep in mind that granting system’s security continuously is an important matter too…so start relying on a VoIP system that is based on old CentOS 5.5 should be avoided! you should select a IP-PBX system mantained by developers that care about its security and efficiency.
IMHO you should give FreePBX Distro 5.211.65 (Stable) a try instead of starting with/using Trixbox CE (start reading the FreePBX Wiki here).
At the same time you should try to define (and clarify yourself first) exactly what will be your network environment/topology and in which way you want your devices should interact with (e.g. your default Gateway/Router IP addressing, your FreePBX Distro system IP addressing, etc…in order to not create Addressing conflicts between devices). Consider that above advices are valid both if you’re just building a test system to play with or if you’re try to building a production system that would go live.