Lawful Intercept (LI)

[nmilojevic]

I am trying to implement Lawful Intercept feature, but there is almost no serious in-depth documentation (or I am unable to find it).

Anyone with first hand experience - please help me out here!

Thanks,

Nikola

[c-charlebois]

Well, it would help if you first defined the feature. I'm not familiar with that feature name. However, knowing the Telephony industry, it is probably known by at least a couple names. So perhaps it's out there, but not called Lawful Intercept.

[nmilojevic]

As far as I know, this is the exact name of the feature (but of course - it is possible, that it is known under other names also). It is about (legally) tapping someones IP phone.

I found only this one usefull document regarding this:

http://www.cisco.com/en/US/partner/tech/tk583/tk799/technologies_design_guide09186a00801b42ff.shtml

Also, it is possible to obtain IOS images with "lawful intercept" addition, so I assume it is the name that Cisco uses.

Regards,

Nikola

[gillins]

The link that you provided indicated that the feature is for use with the BTS environment. I do not think that it possible with out the software functionality that is found in the BTS. There may be other software that can do it but I do not think you can do it with just a gateway. If you have the BTS the link should get you going.

Hope this helps

Scott

[jeff.bankston]

LI is the functional definition for "wiretapping" into a LAN or WAN to permit the logical search for bad guys roaming the network. It came out of CALEA, as far as I know, and it the electronic version of wiretaps that has existed for decades in the physical world.

LI permits the gathering of data at strategic points in the network. ISPs are supposed to build these LI points of entry into their networks to make it easier for law enforcement to rapidly gather intelligence data on "illegal" activities that use a LAN or WAN for moving that suspect information.

Never seen it implemented, no idea how to do it, but that's the idea behind it.

-Jeff

[c-charlebois]

In the Call Center world, that's called Silent Monitoring. Although Silent Monitoring is integrated into the local call control logic and requires specific configuration of the lines to monitored. It sounds like Lawful Intercept is designed to work with the upstream provider, without their knowledge or ability to block. Probably hasn't been an issue yet because so few people have VoIP connections to telcom providers.