Reliability is of the prime concern in critical applications, especially in interactions involving financial transactions. Consider the scenario of fund transfer where we debit one account and credit another account with the same amount of money. We cannot allow either of these transactions to fail or to debit twice in an account as a result of message duplications. Unreliable transport channels like HTTP and non-reliability in message delivery will impede the correctness of the mission critical transactions. This is where the alternatives to SOAP over HTTP, which is being explored.