Cisco Cisco IOS Software Release 12.2(27)SBC

In Cisco IOS Release 12.2(31)SB2 and later releases, lawful intercepts are supported when Routed 
Bridged Encapsulation (RBE) is configured on the router (RFC 1483). 

The Lawful Intercept feature supports Layer 2 and Layer 3 taps. 

Layer 2 taps—Session-based taps that intercept all traffic to and from the session regardless of its 
Layer 3 content. Layer 2 taps are configured via SNMPv3 provisioning and RADIUS-based lawful 
intercepts. Layer 2 taps use the CISCO-TAP2-MIB and CISCO-USER-CONNECTION-TAP-MIB. 

Layer 3 taps—Intercepts at the IP layer that are accessible via SNMPv3 provisioning. Layer 3 taps 
use the CISCO-TAP2-MIB and CISCO-IP-TAP-MIB. 

For additional information on Layer 2 and Layer 3 taps, refer to 

. 

SNMPv3 provisioning lawful intercept requests are initiated by the mediation device via SNMPv3 
messages, and all traffic data going to or from a given IP address or session is passed to a mediation 
device. SNMPv3 provisioning uses the following lawful intercept MIBs: 

CISCO-TAP2-MIB 

CISCO-IP-TAP-MIB 

CISCO-USER-CONNECTION-TAP-MIB 

A RADIUS-based lawful intercept solution enables intercept requests to be sent (via Access-Accept 
packets or CoA-Request packets) to the NAS or to the LAC from the RADIUS server. All traffic data 
going to or from a PPP or L2TP session is passed to a mediation device. Another advantage of 
RADIUS-based lawful intercept is the synchronicity of the solution—the tap is set with Access-Accept 
packets so that all target traffic is intercepted.

For more information about RADIUS-Based Lawful Intercept, see the 

 located at the following URL:

The Communications Assistance for Law Enforcement Act (CALEA) for Voice feature allows the lawful 
interception of voice conversations that are running on voice over IP (VoIP). Although the Cisco 10000 
series router is not a voice gateway device, VoIP packets traverse the router at the edge of the service 
provider’s network. CALEA for Voice is one component of a complete lawful intercept solution, 
consisting of external monitoring and non-Cisco management devices. 

When an approved government agency determines that a telephone conversation is interesting, CALEA 
for Voice copies the IP packets comprising the conversation and sends the duplicate packets to the 
appropriate monitoring device for further analysis. Neither the network administrator nor the calling 
parties is aware that packets are being copied or that the call is being snooped.