 an easy method of conducting trials with various providers to better understand their services. When considering adopting SIP trunks for PSTN access from an SP, conducting a trial implementation is an important method to help determine how successful any large scale 36 SIP Trunking project will be; help to define the process and create a plan for transitioning sites and locations; and help work out any issues that might not have been foreseen in the initial planning and RFP stage. When conducting a SIP trunk trial, you can use several methods. One of the easiest and most effective methods to conduct a trial is to acquire new phone numbers and add an additional dialing pattern to existing UC implementation to enable them to utilize the SIP trunks. This is normally implemented for a small group of users, such as the IT depart- ment or an alpha user community, which can deal with any issues that might result. One idea is to make sure that a company's vendors, including the SP that provides the SIP trunk, communicate with the IT department using the new SIP trunking numbers that have been created. This helps to ensure that the solution is used in a mission critical manner. A pilot implementation needs to include both an inbound and an outbound SIP trunk trial. Another important component of the pilot should be piloting the porting of phone numbers from a TDM trunk to a SIP trunk to better understand the issues that might occur. The porting of DID numbers from a traditional telephony service to a SIP trunk service is often one of the most problematic parts of a transition, and completing a trial run by porting numbers that are not mission critical is an important first step. Some of the best practices for a pilot implementation of SIP trunks follow Ensure the pilot is large enough to realistically gather feedback. For example, a pilot implementation that is of at least ten users and two or more sites can gather more ac- curate information than a small pilot. Ensure that the duration of the pilot is long enough to acc