The CDR format most often used by softswitch vendors to generate CDRs is the Bellcore AMA Format, described in Billing Automatic Message Accounting Format (BAF) Generic Requirements (BAF-GR-1100-CORE). Unfortunately for the next-generation of Voice over IP (VoIP) applications, such as SBC, the BAF format is too telephony specific, and does not contain sufficient provision for IP-centric logging information. (For example, it does not allow for logging of Session Description Protocol (SDP) or RTCP statistics). In addition, the format is not extensible, so it is not possible to define extensions to contain these fields.