Lawful Interception (LI)is the process by which communications traffic is intercepted for delivery to a law enforcement agency (LEA) based on a warrant or a court order.
Lawful Interception Methods
Lawful interception of telecommunications data occurs at access points in communications networks such as satellite feeds, microwave towers, cables and land lines, network switches, cell towers for mobile phones, and even the traditional phone line. Voice over IP (VoIP) network traffic is normally intercepted at an Internet Service Provider.
Typically data is intercepted on the digital segments of PSTN and on IP networks at routers and switches using port mirroring or network taps to capture the packet data at network speeds. Either method duplicates and diverts the packets without interfering with the original data stream. Either the entire data stream or only those packets that satisfy the filter criteria are captured for processing.
Email may be collected using passive intercept methods where the entire e-mail traffic of a provider is captured and redirected for filtering and further processing. If e-mail is encrypted using protocols such as POP3, SMTP, or IMAP each session needs to be decrypted before filtering can take place.
Fax Lawful Interception
VOCAL has utilized its data and fax modem libraries for successful implementation of intercept system solutions for facsimiles. Our Facsimile Lawful Intercept solution provides an integrated suite of software libraries to decode fax communications intercepted over PSTN and IP networks from previously recorded files or real-time sources. Our Fax over IP Image Extraction Library extracts a facsimile image from a file of captured T.38 network traffic or real-time data streams. Together, developers have a range of lawful intercept solutions for monitoring, interception, and recording of fax transmissions.
VOCAL’s lawful intercept software may be licensed as source code or binary. Custom system designs are also available from VOCAL upon request. Please contact us to discuss your specific application needs.
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