Abstract: A computer implemented communications method and protocol is provided which utilizes an XML based communications protocol for security monitoring purposes. The XML based communications protocol consists of numerous modules which receive and convert data messages from varying security devices and sensors, standardize and send converted messages, and encrypt and decrypt said data messages as necessary. With a security system core application (SCA) running on various integrated checkpoint, base station and headquarter based computers and/or other data processing units, the data messages are filtered and transmitted from checkpoint computers to base station computers, then received by a headquarters data processing unit. The SCA running on base station and/or headquarters computers analyzes, reports and logs environmental as well as security events within one or more subject sites.