trial. Install and configure the service. Define a clear test plan and execute it. Start the pilot user community on the SIP trunk. Define Clear Success Criteria You need to be clear on the goals of the Pilot Trial and what conditions would constitute success or failure to your organization. Usually cost benefits are not realized in the trial phase because: The installation is new and can be amortized over only a short period of time by a small number of users. The call volume is extremely low. TDM backup trunking cannot yet be removed. If production service is not implemented after the trial, call traffic might need to be directed back to TDM trunks again, which might add to the trial costs. However, enough information should be available from the results of the pilot to validate the initial cost analysis to determine any adjustments necessary for expected cost savings during production service. Assess Organizational Responsibility Before making arrangements to have the SP install a SIP trunk, ensure that you under- stand organizationally who owns the hand off of traffic from the demarcation point. If you belong to a medium or large enterprise and run the SIP trunk into a data center, there is likely various security policies and equipment and a DMZ, the point any outside con- nectivity has to pass through before it can terminate on your UCB element for secure hand off to your call agent. Ownership of the SIP trunk CPE equipment, and its place- ment relative to the DMZ, varies from one enterprise to the next depending on individual policies and network architectures. If you are a small business that gets an integrated data and SIP trunk service from a provider, installed and delivered by a partner or value-added reseller, this step might be much simpler or nonexistent. Determine the Length of the Trial Decide how long the trial should run. You need a sufficient amount of time to get through the test plan, address any issues found, and allow a reasonable period of use by the pilot user community to provide valid 