J.2 Use of sub-address and calling party number to carry correlation information
33.1083G Security3GPPHandover interface for Lawful Interception (LI)Release 17TS
J.2.1 Introduction
Not all ISDN networks fully support the use of the UUS1 service ETSI EN 300 403‑1 [31]. Some networks may be limited to the transfer of only 32 octets of UUS1 user information rather than the 128 required for full support of the UUS1 service. Some networks may not support UUS1 at all.
This annex describes a procedure to provide correlation information which is appropriate:
1) if a network does not support the delivery of UUS1; or
2) if a network does not support the delivery of 128 octets for UUS1.
If all network involved support the delivery of 128 octets for UUS1 then the procedure (described in this annex) is not appropriate.
The calling party number, the calling party subaddress (CgP Sub) and the called party subaddress (CdP Sub) are used to carry correlation information.
J.2.2 Subaddress options
The coding of a subaddress information element is given in ETSI EN 300 403‑1 [31]. The following options shall be chosen:
Table J.2.1: Subaddress options
|
Option |
Value |
|
Type of subaddress |
user specified |
|
Odd/even indicator |
employed for called party subaddress when no national parameters are used |
J.2.3 Subaddress coding
J.2.3.0 General
The coding of subaddress information shall be in accordance with ETSI EN 300 403‑1 [31].
J.2.3.1 BCD Values
The values 0‑9 shall be BCD coded according to their natural binary values. The hexadecimal value F shall be used as a field separator. This coding is indicated in table J.2.2.
Table J.2.2: Coding BCD values
|
Item |
BCD representation |
|||
|
Bit 4 |
Bit 3 |
Bit 2 |
Bit 1 |
|
|
0 |
0 |
0 |
0 |
0 |
|
1 |
0 |
0 |
0 |
1 |
|
2 |
0 |
0 |
1 |
0 |
|
3 |
0 |
0 |
1 |
1 |
|
4 |
0 |
1 |
0 |
0 |
|
5 |
0 |
1 |
0 |
1 |
|
6 |
0 |
1 |
1 |
0 |
|
7 |
0 |
1 |
1 |
1 |
|
8 |
1 |
0 |
0 |
0 |
|
9 |
1 |
0 |
0 |
1 |
|
Field separator |
1 |
1 |
1 |
1 |
When items are packed two to an octet, the least significant item shall be coded by mapping bit 4 to bit 8, bit 3 to bit 7, etc.
J.2.3.2 Field order and layout
Fields shall be presented into the subaddress in the following order:
Table J.2.3: Fields in the Called Party Subaddress
|
Order |
Field |
|
1 |
Operator-ID |
|
2 |
CIN |
|
3 |
CCLID |
|
4 |
National Parameters |
Table J.2.4: Fields in the Calling Party Subaddress
|
Order |
Field |
|
1 |
Lawful Interception Identifier (LIID) |
|
2 |
Direction |
|
3 |
Service Octets |
Apart from National Parameters, inclusion and format of which is determined by national regulations, each field noted above shall be included, whether empty or not. Each of the Operator-ID, CIN, CCLID, LIID and Direction fields shall end by a field separator.
When sending entity does not have a valid value for either of Operator-ID, CIN, CCLID, LIID or Direction fields, then the field is considered empty and it shall be represented only by its field separator.
Table J.2.4A: Example of how field separator should be used when field is empty
|
Bits |
Octets |
||||||||
|
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
||
|
Called party subaddress identifier |
1 |
||||||||
|
Length of called party subaddress contents |
2 |
||||||||
|
Type of subaddress = user specified, odd/even indicator |
3 |
||||||||
|
Operator-ID |
Operator-ID |
4 |
|||||||
|
Operator-ID |
Operator-ID |
5 |
|||||||
|
Field separator |
Operator-ID |
6 |
|||||||
|
CCLID |
Field separator |
7 |
|||||||
|
CCLID |
CCLID |
8 |
|||||||
|
CCLID |
CCLID |
9 |
|||||||
|
CCLID |
CCLID |
10 |
|||||||
|
Field separator |
CCLID |
11 |
|||||||
|
12 |
|||||||||
|
13 |
|||||||||
|
14 |
|||||||||
|
15 |
|||||||||
|
(see note) |
16 |
||||||||
|
17 |
|||||||||
|
18 |
|||||||||
|
19 |
|||||||||
|
20 |
|||||||||
|
21 |
|||||||||
|
22 |
|||||||||
|
23 |
|||||||||
|
NOTE: The Octets after the final field (CCLID) of the Called Party Subaddress are reserved for national use, e.g. for authentication purposes. |
|||||||||
The parameters within the Information Elements "Called Party Subaddress" and "Calling Party Subaddress" are variable. Because of this variable length the parameters may start in different octets in the related Information Element. i.e. in the Calling Party Subaddress the Direction can be found in octet 17 when the LIID is 25 digits long (table J.2.6).
When the LIID is composed of less than 25 digits, the field separator and direction indicator "moves up" and the rest of the octets is spare till octet 19. Between the last digit of the LIID and the Direction is always a Field separator (value F). Also after the "Direction" one Field Separator is given. The last Field separator separates the relevant data from the spare part. So the location of the TMR and the other service Octets below are fixed within the Subaddress. The total length of the Calling Party Subaddress is fixed to 23 octets (including the two Mobile service octets) or 21 octets (without the two Mobile service octets).
The Service Octets as available shall always be mapped into octets 19 to 23 of the Calling Party Subaddress, as appropriate. If one of the parameters TMR, BC or HLC is not available, the octet shall be filled with "FF" hex.
In relation to Mobile Bearer Service Code and Mobile Teleservice Code, the mapping of the values into octets 22 and 23, respectively, shall be done as follows:
i. if both, Mobile Bearer Service Code and Mobile Teleservice Code are provided by signalling, octets 22 and 23, shall be present, each containing the mapped value;
ii. if Mobile Bearer Service Code is provided by signalling, and Mobile Teleservice Code is NOT provided by signalling, octet 22 shall be present containing the mapped value, and octet 23 shall be omitted;
iii. if Mobile Teleservice Code is provided by signalling, and Mobile Bearer Service Code is NOT provided by signalling, there are two implementation options:
1) neither octet 22 nor octet 23 shall be present;
2) octet 22 shall be filled with "FF" hex and octet 23 shall be present containing the mapped value;
iv. if neither Mobile Teleservice Code nor Mobile Bearer Service Code is provided by signalling, neither octet 22 nor octet 23 shall be present.
As an option the Calling Party Subaddress and Called Party Subaddress may have a variable length. The length is given in octet 2.
When the LIID is composed of less than 25 digits in the Calling Party Subaddress, the Field separator, Direction indicator, Field separator and all the Service Octets "moves up".
National Parameters in a variable length Called Party Subaddress may have variable length.
Table J.2.5 represent called party subaddress and table J.2.6 calling party subaddress with the maximum length of the identifiers.
Table J.2.5: Called Party Subaddress
|
Bits |
Octets |
||||||||
|
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
||
|
Called party subaddress identifier |
1 |
||||||||
|
Length of called party subaddress contents |
2 |
||||||||
|
Type of subaddress = user specified, odd/even indicator |
3 |
||||||||
|
Operator-ID |
Operator-ID |
4 |
|||||||
|
Operator-ID |
Operator-ID |
5 |
|||||||
|
Field separator |
Operator-ID |
6 |
|||||||
|
CIN |
CIN |
7 |
|||||||
|
CIN |
CIN |
8 |
|||||||
|
CIN |
CIN |
9 |
|||||||
|
CIN |
CIN |
10 |
|||||||
|
CCLID |
Field separator |
11 |
|||||||
|
CCLID |
CCLID |
12 |
|||||||
|
CCLID |
CCLID |
13 |
|||||||
|
CCLID |
CCLID |
14 |
|||||||
|
Field separator |
CCLID |
15 |
|||||||
|
see note |
16 |
||||||||
|
17 |
|||||||||
|
18 |
|||||||||
|
19 |
|||||||||
|
20 |
|||||||||
|
21 |
|||||||||
|
22 |
|||||||||
|
23 |
|||||||||
|
NOTE: The Octets after the final field (CCLID) of the Called Party Subaddress are reserved for national use, e.g. for authentication purposes. |
|||||||||
Table J.2.6: Calling Party Subaddress
|
Bits |
Octets |
|||||||||
|
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
|||
|
Calling party subaddress identifier |
1 |
|||||||||
|
Length of calling party subaddress contents |
2 |
|||||||||
|
Type of subaddress = user specified, odd/even indicator according to the amount of BCD-digits |
3 |
|||||||||
|
LIID |
LIID |
4 |
||||||||
|
LIID |
LIID |
5 |
||||||||
|
LIID |
LIID |
6 |
||||||||
|
LIID |
LIID |
7 |
||||||||
|
LIID |
LIID |
8 |
||||||||
|
LIID |
LIID |
9 |
||||||||
|
LIID |
LIID |
10 |
||||||||
|
LIID |
LIID |
11 |
||||||||
|
LIID |
LIID |
12 |
||||||||
|
LIID |
LIID |
13 |
||||||||
|
LIID |
LIID |
14 |
||||||||
|
LIID |
LIID |
15 |
||||||||
|
Field separator |
LIID |
16 |
||||||||
|
Field separator |
Direction |
17 |
||||||||
|
spare |
spare |
18 |
||||||||
|
ITU-T Recommendation Q.763 [29] TMR (see note 1) |
19 |
|||||||||
|
ITU-T Recommendation Q.931 BC [34] octet 3 (see note 2) |
20 |
|||||||||
|
ITU-T Recommendation Q.931 HLC [34] octet 4 (see note 3) |
21 |
|||||||||
|
Mobile Bearer Service Code (see note 4) |
22 |
|||||||||
|
Mobile Teleservice Code (see note 5) |
23 |
|||||||||
|
NOTE 1: If available, the Transmission Medium Requirement according to EN 300 356 [30]. If not available, the value is "FF" hex. NOTE 2: If available, only octet 3 of the Bearer Capability I.E. according to EN 300 403 [31] If not available, the value is "FF" hex. NOTE 3: If available, only octet 4 of the High Layer Compatibility I.E. according to NOTE 4: If available, the Mobile Bearer Service Code according to TS 29.002 [4], clause 17.7.10. If not available, the octets 22 and 23 (even if the mobile teleservice code is available) shall not be transmitted. NOTE 5: If available, the Mobile Teleservice Code according to TS 29.002 [4], clause 17.7.9. If not available, the octet 23 shall not be transmitted. |
||||||||||
J.2.4 Field coding
J.2.4.0 Introduction
Each field shall employ decimal coding, except for the Service Octets (octets 19-23 of the CgP Sub) and the octets reserved for national use (octets 16-23 of the CdP Sub). Other values are not permitted.
J.2.4.1 Direction
The direction field shall be coded as follows:
Table J.2.7: Direction coding
|
Indication |
Value |
|
Mono mode (combined signal) (historic) |
0 |
|
CC from target |
1 |
|
CC to target |
2 |
J.2.4.2 Coding of the Calling Party Number
The Network Element Identifier (NEID) shall be carried by the calling party number information element. The coding shall be as follows, depending on the type of network access (see note 1):
|
Numbering plan identification: |
ISDN/telephony numbering plan (Recommendation E.164) |
|
Nature of address: |
As specified in ITU-T Recommendation Q.731.3 (see note 1) (e.g. national (significant) number or international number) (in case of ISUP signalling) |
|
Type of number: |
As specified in ITU-T Q.951, EN 300 092 (e.g. unknown, subscriber number, national number or international number), and Network Operator specific type of access (BRA or PRA) (in case of DSS1 signalling, see note 2 and 3) |
|
Screening indicator: |
Network provided (in case ISUP signalling) |
|
Screening indicator: |
User-provided, not screened (in case of DSS1 signalling, see note 3) |
|
Presentation indicator: |
Presentation allowed |
NOTE 1: The relevant national specification of the Signalling System Number 7 may also specify requirements on the Nature of address for national specific use in national variants of ISUP.
NOTE 2: Usually, the IIF respectively the Mediation Function is connected to the network by links using Signalling System Number 7 and ISDN User Part (ISUP), whereby the parameters are coded according to ITU‑T Recommendation Q.763 [29]. But in some cases, the IIF respectively the Mediation Function may be connected via a Basic Rate Access or a Primary Rate Access using D-Channel signalling, whereby the parameters are coded according to ETSI EN 300 356 [30].
NOTE 3: The network will perform screening, i.e. the number will arrive at the LEMF as "user-provided, verified and passed" with the appropriate "type of number" indicator. A network provided number shall also be accepted at the LEMF.
J.2.5 Length of fields
The length of the identifiers is variable. The maximum and recommended minimum length of each field is given in table J.2.8:
Table J.2.8: Field length
|
Field |
Minimum length (decimal digits) |
Maximum length (decimal digits) |
Maximum length (Half-Octets) |
I.E. |
|
Operator ID |
2 |
5 |
5 + 1 |
CdP Sub |
|
CIN |
6 |
8 |
8 + 1 |
CdP Sub |
|
CCLID |
1 |
8 |
8 + 1 |
CdP Sub |
|
LIID |
2 |
25 |
25 + 1 |
CgP Sub |
|
Direction |
1 |
1 |
1 + 1 |
CgP Sub |
|
Service Octets |
10 |
CgP Sub |
Annex K (normative):
VoIP HI3 Interface