The Average Call Duration (ACD) is calculated by taking the sum of billable seconds (billsec) of answered calls and dividing it by the number of these answered calls br VoIP providers mostly offer Least Cost Routing (LCR) to ensure higher quality of service. br LCR efficiently and successfully transfers your calls at a reasonable cost. It saves time and br effort for routing international calls by using most cost effective method for transferring traffic. br Thus improving the overall quality of the service provided.In order to route a call effectively, certain issues should be considered and improved br accordingly such as: br Average Call Duration (ACD) br It is the total amount of time taken by the call. In case of lower ACD, it is expected br that the quality of the connection is not good enough for the subscriber to continue br the call. br Post Dial Delay (PDD) br On dialing phone number, either there is a ring or busy tone that tells us that whether br the called party is available or not. The time elapsed between dialing a number and br hearing a tone is referred to as Post Dial Delay (PDD). In case of higher PDD, it is br expected that there is no dial tone for the subscriber to initiate a call. br Answer-Seize Ratio (ASR) br It is the ratio between the successful calls and the attempted calls that cannot be br answered for any reason. In case of lower ASR, it is expected that the route provided br to the call is choked-up for the subscribers to make phone calls.