etwork layer to gather and report statistics about the quality of the voice con- nections. One methodology to determine latency and packet loss in a network, which are important components of quality, is the use of the IP Service Level Availability (IP SLA) Probe used in Cisco IOS. Other, more advanced versions of network-based call quality scoring use a virtual or physical DSP to provide call quality scoring. This information would then naturally lead to enforced SLAs based on call quality monitoring. A second advanced feature of SIP trunking services that is developing is the sharing of presence information. Currently, federation of presence is normally done between two different entities using an Internet protocol and a tunnel that shares information. This information is normally dependent upon the presence application that exists within the organization. For example, it is easy for two companies that both utilized Microsoft OCS services to federate and share presence information between them. It is also possible for a service provider to act as the central depository for presence information from multiple companies. As such, companies utilizing this SP would share presence information. These federated presence information services often use portions of the SIP protocol; however, the SIP trunking services offered are distinct from the presence services offered. Due to this trend, an additional developing service trend is for the SP to utilize a standards-based mechanism for exchanging presence information over a SIP trunk, and as such, the same trunk that is used to interconnect for PSTN access service and Video Interconnection service can be used for sharing presence information among companies. The benefit of using the same connection for advanced SIP trunking services, such as presence federation and call quality scoring, is the ability to utilize the same policy across any media or service that share that pipe. Another advanced SIP trunking trend is SP offering more supplementary services across a SIP trun