Naldi (2002) presented a Markov chain model based analysis for the user’s behaviour in a simple scenario of two competitors. The model is applied to predict influence of both parameters (blocking probability and initial preference) on the traffic distribution between the operators. It is also shown that smaller blocking competitors can be benefited from call-by-call basis assumption. In this paper this criteria of Call-by-call attempt is converted into two call attempts and new mathematical results are derived. A comparative study between call-attempts is made with Naldi (2002) expressions. It is found that, by two-call attempt model, the operator gains more traffic than one-call attempt.