I am searching for tools available as opensource where we can create networks and capture packets ...
Please provide the link so that i can download and play around it.
You need quagga which is a opensource and comes with nice management panel along with SNMP control also. In short you can create the light weight switch or router from your PC/laptop. I have used it personnaly to create OSPF based network in the past.
Download the code http://code.quagga.net/
Summary http://en.wikipedia.org/wiki/Quagga_(software)
There is a use case in which two machines are located in same network or different network but both are reachable to each other. Can remotely captured packets in one machine be seen in wireshark running in another machine on real time basis ?
Have anyone used any opensource compiler for encoding and decoding of S1Ap/ X2Ap message as it uses PER aligned version