tral infor- mation technology (IT) organization. Simply completing the steps to determine a com- plete and an accurate list of equipment, application, and costs involved in trunking between application and to the SPs for PSTN access can be an important step and can uncover areas of savings that can be further examined. These might include the following: A trade-in of credit for unused or underused trunking hardware Redundant or unused SP trunking charges that can be consolidated or minimized Features, such as call waiting, being purchased but are not required Inbound Direct Inward Dial (DID) numbers being purchased but are not utilized One method you can use to ensure that all installed trunking is considered and recorded is to start with the accounting department. Specifically, utilize the bills paid to the vari- ous SPs as the first step to gathering an accurate count of all trunking that occurs. Some trunks might have been ordered outside of the IT infrastructure and their consolidation under a centralized bill can result in major cost savings. 34 SIP Trunking In summary, an important first step to determine the current state of trunking infrastruc- ture at a company includes Listing and reconciling all applications that utilize PSTN connectivity. One important caveat in this is the percentage of fax calls that exists. Fax has unique challenges when transitioning to SIP trunks, and the percentage of fax traffic can be an important fac- tor in selecting the right SIP trunk provider. Listing all TDM trunking services and features on these trunks (for instance, call waiting, voicemail, and SO on) purchased by the company. You can accomplish this by examining the charges levied by the SPs. Determining if there are any nonstandard applications, such as postage machines or alarm systems, that utilize PSTN connectivity. When a final audit is completed, you should have a full assessment of the company's cur- rent trunking costs and equipment infrastructure. The larger the current trunking infra- structure, the greater