Lawful Intercept concepts

LI description

Lawful Intercept (LI) is a term that describes the interception and monitoring of network subscriber traffic by authorized agencies for law-enforcement purposes. A subscriber whose traffic is intercepted using LI is called a target. The LI target traffic is replicated by a service mirror that uses subscriber information as the match criteria.

LI characteristics

LI has the following characteristics.

• LI is not detectable by a target subscriber.

• LI traffic is delivered separately from other network traffic.

• LI alarms are displayed only for authorized LI users.

• LI configuration information is stored in a separate and encrypted file.

• LI uses TLS to secure the required communication channels

LI functions

LI functions are managed separately from other NFM-P functions. LI mirroring is a special type of service mirroring that requires the following:

• on each LI NE in a mirror service:

  • SSH user security

  • an LI user profile

  • a user account that has LI privileges

• on the NFM-P:

  • TLS on the single-user GUI clients, client delegate servers, and JMS server

  • a user account that has LI privileges

  • an assigned Lawful Interception Management scope of command role

  • an LI mediation policy

Note: The NFM-P blocks the association of LI mediation security to 7750 SR NEs that contain '-NL' in their software version descriptor.

LI configurations on 7750 SR NEs with a non-LI image do not complete because the NE does not have LI mediation security.