B.5 Information flows for Lawful Interception invocation (informative)

03.333G security3GPPLawful InterceptionStage 2TS

The following figures show the information flows for the invocation of Lawful Interception for GPRS and typical scenarios. The figures show some of the basic signalling messages of the target packet data communication and the events on the X2P and X3P-interfaces. The dotted lines indicate signalling depending on whether IP and/or IRI information has been requested. GGSN may setup/release packet tunnels and send IRI information depending on national requirements.

The use of the GGSN for interception is a national option.

B.5.1 GPRS attach

Figure B15 shows the interception of a basic GPRS attach where the mobile (A) is the target for interception.

Figure B15: Interception of mobile originated GPRS attachment

B.5.2 Mobile originated GPRS detach

Figure B16 shows the interception of a mobile originated GPRS detach where the originating mobile (A) is the target for interception.

Figure B16: Interception of mobile originated GPRS detachment

B.5.3 Network initiated GPRS detach

Figure B17 shows the interception of a network initiated (by SGSN or HLR) GPRS detach where the mobile (A) is the target for interception.

Figure B17: Interception of network initiated GPRS detach.

NOTE: * Additional signals in case of HLR initiated

B.5.4 Intra SGSN Routing Area Update

Figure B18 shows the interception of an Intra Routing Area Update where the mobile (A) is the target for interception. The sequence is the same for the combined RA / LA Update procedure but additional signalling is performed between the SGSN and MSC/VLR, HLR and the old MSC/VLR before the Routing Area Update Accept message is sent to the MS.

Figure B18: Interception of an Intra Routing Area Update

B.5.5 Inter SGSN Routing Area Update

Figure B19 shows the interception of an Inter Routing Area Update where the mobile (A) is the target for interception. The sequence is the same for the combined RA / LA Update procedure but additional signalling is performed between the SGSN and MSC/VLR, HLR and the old MSC/VLR before the Routing Area Update Accept message is sent to the MS. In case of PDP context not being active less signalling is required.

Figure B19: Interception of an Inter Routing Area Update

B.5.6 PDP Context Activation

Figure B20 shows the interception of a PDP Context activation where the mobile (A) is the target for interception. The sequence for a network initiated PDP Context activation is analogous but is preceded by the SGSN sending a Request PDP Context Activation to the MS.

Figure B20: Interception of a PDP Context Activation

B.5.7 Start of interception with PDP context active

A tunnel is established to DF3P and an event is sent to DF2P.

B.5.8 MS initiated PDP Context Deactivation

Figure B21 shows the interception of a MS initiated PDP Context deactivation where the mobile (A) is the target for interception.

Figure B21: Interception of a PDP Context Deactivation

B.5.9 Network initiated PDP Context Deactivation

Figure B22 shows the interception of a Network initiated PDP Context deactivation where the mobile (A) is the target for interception. The GGSN may send, (depending on national requirements) the PDP Context deactivation and release the GPRS packet tunnel after the Delete PDP Context Response has been sent or received, (signalling between the SGSN and the GGSN is not shown here).

Figure B22: Interception of a Network initiated PDP Context Deactivation

B.5.10 SMS

Figure B23 and B24 shows the interception of a Mobile-terminated SMS and a Mobile-originated SMS transfer where the mobile (A) is the target for interception.

Figure B23: Interception of a Mobile-terminated SMS transfer

Figure B24: Interception of a Mobile-originated SMS transfer

Annex C (informative):
Change history

Change history

Date

TSG #

TSG Doc

CR

Rev

Cat

Subject/Comment

Old

New

02-1999

SMG#28

Specification to SMG#28 for approval
(only circuit switched LI)

2.0.0

7.0.0

A001

1

B

Addition of lawful interception for GPRS

7.0.0

7.1.0

12-2000

SA_10

SP-000623

002

F

Addition of parameters to the X3-Interface

7.1.0

7.2.0

12-2000

SA_10

SP-000670

004

1

F

Deletion of mono-mode and addition of optimal routeing

7.1.0

7.2.0