Thank you for your reply.
I was exploring through Internet for the solution specific to my scenario, but i could gather that I may need to configure the bridge in my linux machine. In this regard, i am not clear whether it will work for me under the following situation.
etho - has the broadband connection with static public IP using ppp0
eth1 - our private network with multiple IP addresses
cisco router 2503 - as gateway to connect hour HO for erp access
If your any idea please share with me.