8.1 Base station system network functions
8.1.3 Testing of the BSSMAP and RR functions
8.1.3.12 Ciphering mode setting
NOTE: The purpose of the ciphermode control procedure is, after authentication, to initialize and synchronize the stream ciphering devices in the MS and BSS. The MS and the MSC know already from the authentication procedure the cipher key Kc, and in this procedure this key is passed to the BSS.
Any failure during the ciphermode control procedure will be regarded as a lower layer failure and will therefore not be tested explicitly.
8.1.3.12.1 Cipher Mode Complete Test Purpose
To verify the ciphering mode setting procedure, the procedure is completed by a Cipher Mode Complete message from the Mobile Station.
Test Case Initial Setup
A dedicated resource shall be established between the radio interface and the MSC-interface. Ciphering shall not be activated.
Description
1. A CIPHER MODE COMMAND message shall be input on the MSC-interface containing the Algorithm identifier octet set to "GSM user data encryption version 1" and the key Kc in the Encryption information element as specified in GSM 08.08 [10], 3.2.2.10. The response on any interface shall be recorded.
2. At the reception on the Air interface of the message CIPHERING MODE COMMAND, the BSSTE shall start deciphering and enciphering on the radio interface and then input a CIPHERING MODE COMPLETE message on the radio interface on the main signalling link. The response on any interface shall be recorded.
3. The BSSTE shall input any arbitrary DTAP message on the MSC-interface. The response on any interface shall be recorded.
Message flow
MS BSS MSC CIPHER MODE CMD
CIPH MODE CMD
<--- start deciphering BSS Layer 2 frame
---> start enciphering BSS CIPH MODE COM
--->
CIPHER MODE COM
--->
DTAP message
<---The messages from the BSSTE will be:
1. CIPHER MODE COMMAND on the a interface, coded as specified in GSM 08.08 [10], 3.2.1.30, with in the Encryption Information:
Algorithm identifier = "GSM user data encryption version 1"
Key Kc.
2. CIPHERING MODE COMPLETE on the Air interface, coded as specified in GSM 04.08 [4], 9.1.10.
3. DTAP MESSAGE Conformance Requirements
In step 1, a CIPHERING MODE COMMAND message shall occur on the radio interface on the main signalling link. The message shall not be enciphered.
In step 2, the CIPHER MODE COMPLETE message shall occur on the MSC-interface.
In step 3, the chosen DTAP message shall occur on the radio interface on the main signalling link. The message shall be enciphered.
The messages from the BSS shall be:
1. CIPHERING MODE COMMAND, coded as specified in GSM 04.08 [4], 9.1.9 with:
Ciphering mode setting = "Start Ciphering".
2. CIPHER MODE COMPLETE, coded as specified in GSM 08.08 [10], 3.2.1.31.
3. DTAP message.
Requirement reference 04.08 [4], 3.4.7.
08.08 [10], 3.1.14.
8.1.3.12.2 DTAP message Test Purpose
To verify the ciphering mode setting procedure, the procedure is completed by a DTAP message from the Mobile Station.
Test Case Initial Setup
A dedicated resource shall be established between the radio interface and the MSC-interface. Ciphering shall not be activated.
Description
1. A CIPHER MODE COMMAND message shall be input on the MSC-interface containing the Algorithm identifier octet set to "GSM user data encryption version 1" and the key Kc in the Encryption information element as specified in GSM 08.08 [10], 3.2.2.10. The response on any interface shall be recorded.
2. The BSSTE shall start deciphering and enciphering on the radio interface and then input an I frame containing any DTAP message on the radio interface on the main signalling link. The response on any interface shall be recorded.
3. The BSSTE shall input any arbitrary DTAP message on the MSC-interface. The response on any interface shall be recorded.
Message flow
MS BSS MSC CIPHER MODE CMD
CIPH MODE CMD
<--- start deciphering BSS Layer 2 frame
---> start enciphering BSS DTAP message 1
--->
DTAP message 1
--->
DTAP message 2
DTAP message 2
<---The messages from the BSSTE will be:
1. CIPHER MODE COMMAND on the A-interface, coded as specified in GSM 08.08 [10], 3.2.1.30, with in the Encryption Information:
Algorithm identifier = "GSM user data encryption version 1".
Key Kc.
2. DTAP MESSAGE 1 on the radio interface.
3. DTAP MESSAGE 2 on the MSC interface.
Conformance Requirements
In step 1, a CIPHERING MODE COMMAND message shall occur on the radio interface on the main signalling link. The message shall not be enciphered.
In step 2, the chosen DTAP message shall correctly be deciphered and shall occur on the MSC-interface.
In step 3, the chosen DTAP message shall occur on the radio interface on the main signalling link. The message shall be enciphered.
The messages from the BSS shall be:
1. CIPHERING MODE COMMAND, coded as specified in GSM 04.08 [4], 9.1.9 with:
The Ciphering mode setting = "Start Ciphering".
Requirement reference 04.08 [4], 3.4.7 08.08 [10], 3.1.14
8.1.3.12.3 IMEISV request without starting encryption Test Purpose
The purpose of this test is to make sure that an IMEISV request is accepted by the BSS, even when encryption is not required.
Test Case Initial Setup
A dedicated resource shall be set up between the A-interface and the Um-interface. Ciphering shall not be activated.
Description
1. A CIPHER MODE COMMAND Message shall be input on the A-interface containing the Ciphering Response Mode set to 1 and no encryption is required. The response on any interface shall be recorded.
2. The BSSTE shall input the CIPHER MODE COMPLETE message on the Um-interface. The response on any interface shall be recorded.
Message flow
MS BSS MSC CIPHER MODE CMD
CIPHER MODE CMD
CIPHER MODE COM
--->
CIPHER MODE COM
--->
The messages from the BSSTE will be:
1. CIPHER MODE COMMAND - GSM 08.08 [10], 3.2.1.30 Layer 3 header information
Encryption information (encryption not required)
Cipher response mode (IMEISV must be included by the MS)
2. CIPHER MODE COMPLETE - GSM 04.08 [4], 9.1.10 Mobile equipment identity (including IMEISV) Conformance Requirements
In step 1, a CIPHER MODE COMMAND shall occur on the Um-interface asking for no encryption and requesting IMEISV.
In step 2, a CIPHER MODE COMPLETE message shall occur on the A-interface.
The messages from the BSS shall be:
1. CIPHER MODE COMMAND - GSM 04.08 [4], 9.1.9 Ciphering mode setting (no ciphering) Cipher response (IMEISV shall be included) 2. CIPHER MODE COMPLETE - GSM 08.08 [10], 3.2.1.31
Layer 3 Message Contents (including IMEISV) Requirement reference
GSM 08.08 [10], 3.1.14 GSM 04.08 [4], 3.4.7
8.1.3.12.4 IMEISV request with invalid answer Test Purpose
The purpose of this test is to make sure that the BSS does not consider erroneous a lack of IMEISV in the Cipher Mode Complete message from MS side.
Test Case Initial Setup
A dedicated resource shall be set up between the A-interface and the Um-interface. Ciphering shall not be activated.
Description
1. A CIPHER MODE COMMAND Message shall be input on the A-interface containing the Ciphering Response Mode set to 1. The response on any interface shall be recorded.
2. The BSSTE shall input the CIPHER MODE COMPLETE message on the Um-interface. The message does not contain IMEISV as requested with Ciphering Response Mode in the CIPHER MODE COMMAND. The response on any interface shall be recorded.
Message flow
MS BSS MSC CIPHER MODE CMD
CIPHER MODE CMD
CIPHER MODE COM
--->
CIPHER MODE COM
--->
The messages from the BSSTE will be:
1. CIPHER MODE COMMAND - GSM 08.08 [10], 3.2.1.30 Layer 3 header information
Encryption information
Cipher response mode (IMEISV must be included by MS) 2. CIPHER MODE COMPLETE - GSM 04.08 [4], 9.1.10
(no mobile equipment identity included) Conformance Requirements
In step 1, a CIPHER MODE COMMAND shall occur on the Um-interface.
In step 2, a CIPHER MODE COMPLETE message shall occur on the A-interface.
The messages from the BSS shall be:
1. CIPHER MODE COMMAND - GSM 04.08 [4], 9.1.9 Ciphering mode setting
Cipher response (IMEISV shall be included) 2. CIPHER MODE COMPLETE - GSM 08.08 [10], 3.2.1.31
Layer 3 Message Contents (not including IMEISV) Requirement reference
GSM 08.08 [10], 3.1.14 GSM 04.08 [4], 3.4.7
8.1.3.12.5 IMEISV not requested with invalid answer Test Purpose
The purpose of this test is to make sure that the BSS does not consider erroneous a Cipher Mode Complete message from MS side including IMEISV even if not requested.
Test Case Initial Setup
A dedicated resource shall be set up between the A-interface and the Um-interface. Ciphering shall not be activated.
Description
1. A CIPHER MODE COMMAND Message shall be input on the A-interface containing the Ciphering Response Mode set to 0. The response on any interface shall be recorded.
2. The BSSTE shall input the CIPHER MODE COMPLETE message on the Um-interface. The message does contain Layer 3 Message Contents with IMEISV. The response on any interface shall be recorded.
Message flow
MS BSS MSC CIPHER MODE CMD
CIPHER MODE CMD
CIPHER MODE COM
--->
CIPHER MODE COM
--->
The messages from the BSSTE will be:
1. CIPHER MODE COMMAND - GSM 08.08 [10], 3.2.1.30 Layer 3 header information
Encryption information
Cipher response mode (IMEISV must not be included) 2. CIPHER MODE COMPLETE - GSM 04.08 [4], 9.1.10
Mobile equipment identity (including IMEISV) Conformance Requirements
In step 1, a CIPHER MODE COMMAND shall occur on the Um-interface.
In step 2, a CIPHER MODE COMPLETE message shall occur on the A-interface.
The messages from the BSS shall be:
1. CIPHER MODE COMMAND - GSM 04.08 [4], 9.1.9 Ciphering mode setting
Cipher response (IMEISV shall not be included) 2. CIPHER MODE COMPLETE - GSM 08.08 [10], 3.2.1.31
Layer 3 Message Contents (including IMEISV) Requirement reference
GSM 08.08 [10], 3.1.14 GSM 04.08 [4], 3.4.7