CUBE, which terminates the VoIP call leg on a DSP and re-originates it on the other side-because a DSP termination is involved, actual statistics on both call legs are available from the DSP. Another method is snooping on the Real-Time Control Protocol (RTCP) statistics as they travel through the border and to report on some of these statistics. However, many VoIP endpoints do not support RTCP. The IP Service Level Agreement (IP SLA) Real-Time Transport Protocol (RTP)-based VoIP operation feature provides another method to provide statistics. This Cisco IOS feature uses test calls to a DSP to determine values for voice quality metrics over different net- work segments. The CUBE can be either the originator or the destination of the IP SLA probes to provide readings for voice quality statistics up to your network border. There is also the Cisco IOS Voice Performance Statistics on Cisco Gateways feature (using the command voice csr statistics) that collects call statistics such as active calls, failed calls, packet loss, latency, and jitter. Billing Typically, service providers bill without any information from the enterprise. Call detail records (CDR) from the CUBE can provide a consolidated aggregate view of calls sent and received on the SIP trunk and can be used to validate the service provider's billing. Drawing billing records from your border element also provides a consolidated view of SIP trunk traffic use if you share a SIP trunk among multiple CUCM clusters or IP-PBXs. Cisco IOS Software CDRs contain calling and called numbers, local and remote node names, data and time stamp, elapsed time, call failure class fields, and some vendor- specific attribute (VSA) fields. Each call through the CUBE is considered to have two legs. Start and Stop records are generated for each call leg. These records can be sent to a RADIUS server or retrieved with Simple Network Management Protocol (SNMP) polling using the dial-control Management Information Base (MIB). QoS Marking TDM voice gateways originated IP packets and, 