Nortel DMS-100 Trunk Subgroup Table (TRKSGRP)

Table Name

Trunk Subgroup Table

Functional Description of Table TRKSGRP

Table TRKSGRP lists the supplementary information for each subgroup that is assigned to one of the trunk groups listed in table TRKGRP.

Input data must be specified for at least one subgroup for each trunk group listed in table TRKGRP, excluding trunk groups that are defined in table TRKSGRP as Maintenance Group (MAINT) type.  No data is required in table TRKSGRP for the MAINT trunk group type.

For TRKGRP type GTRK (Global Trunks), table TRKSGRP is replaced by table TRKSIGPF.

The following table lists the signaling systems available in Nortel DMS switches:

Nortel DMS Signaling Systems

Signaling System        See Subtable
C7UP                    TRKSGRP type C7UP 
CCITT6                  TRKSGRP type CCITT6 
DPNSS                   TRKSGRP type DPNSS 
DS0TL                   TRKSGRP type DS0TL 
FST                     TRKSGRP type FST
G1TR7                   TRKSGRP type G1TR7
ISDN                    TRKSGRP type ISDN
JSTD                    TRKSGRP type JSTD 
MAINT                   Not Required 
N5                      TRKSGRP type N5 
NOSIG                   TRKSGRP type NOSIG 
R1 or R1N5              TRKSGRP type R1/R1N5
R2                      TRKSGRP type R2
SIGSYS                  TRKSGRP type SIGSYS 
STD                     TRKSGRP type STD 
TUP                     TRKSGRP type TUP 
UKSTD                   TRKSGRP type UKSTD 
X.25                    TRKSGRP type X25 
X.75                    TRKSGRP type X75


Office Parameters for Timing on Trunks

A list of standard office parameters in table OFCOPT (Office Options) that define timing (wink or delay dial) on trunks includes:

Restricting Access to Table TRKSGRP

Access to table TRKSGRP can be restricted by datafilling table CUSTPROT (Customer Protection).  For United Kingdom operating companies, access to table TRKSGRP must be restricted by datafilling table CUSTPROT.  Because the signaling parameters are defined in table CUSTPROT, any alterations affect the integrity of United Kingdom operating companies networks.

Data Restrictions for Utility Telemetry Trunks

Utility Telemetry (UT) trunks connect a Central Office Service Unit (COSU) to a DMS switch.  When connected by UT trunks, the COSU can initiate and control telemetry calls to subscriber lines through the DMS switch, which attempts to establish the connections.

For subgroups associated with UT trunk groups, no changes have been made to table TRKSGRP.  However, certain restrictions are imposed on the UT data specified in table TRKSGRP.  These restrictions are shown in the following table:

Restricted Fields for UT Trunk Subgroups

Field Name       Permissible Value
DIR              IC 
IPULSTYP         MF 
ISTARTSG         WK 
OVLP             N
CCONT            NO
RNGBCK           NO
ESUPR            N 
SAT              N 
REMBSY           N 
DIALMODE         M
ECSTAT           UNEQ

Default Tuple Added to Table TRKSGRP for Trunk Group DTU

The following table shows the default values that are added to table TRKSGRP, after table TRKGRP is datafilled for trunk group type DTU:

Default Values for DTU Trunk Group

Field Name        Value
SGRPKEY           DTU 1
CARDCODE          4X23AA
SCRPVAR           NOSIG 
SIGDATA           STD 
DIR               OG 
OPULSTYP          NP
OSTARTSG          WK 
IDIGTIME          0 
NUMSTOPS          0
CCONT             NO 
RNGBCK            NO
ESUPR             N 
SAT               N 
REMBSY            N 
TRKGRDTM          17

ISUP Integrated Business Network Trunk Datafill

ISUP Integrated Business Network (IBN) trunks are datafilled in much the same manner as basic IBN trunks.  Table CLLI is datafilled first, then table TRKGRP is datafilled with a trunk group type of IBNTO (Outgoing), IBNTI (Incoming), or IBNT2 (Two Way).  After datafilling table TRKGRP, datafill table TRKSGRP to identify an IBN trunk group as an ISUP trunk group by setting field SIGDATA to C7UP.

After table TRKSGRP is datafilled, table ISUPDEST (CCS7 ISDN User Part Destination) must be datafilled to identify the routeset associated with the ISUP IBN trunk subgroup.  After table ISUPDEST is datafilled, trunks can be added to table TRKMEM (Trunk Member) as normal.  Table C7TRKMEM (CCS7 Trunk Member) must be datafilled to associate the ISUP IBN trunks with a circuit identification code.

Note 1:  The DMS switch rejects the table TRKSGRP tuple for those ISUP IBN trunks that do not have appropriate datafill in table TRKGRP.  After you enter information in table TRKSGRP, the system generates an information message to indicate any datafill errors.

Note 2:  It is not possible to have one trunk subgroup datafilled with C7UP signaling and another datafilled with non-C7UP signaling within the same trunk group type.

Note 3:  Table TKCVDATA (Mass Trunk Conversion Data) provides a mechanism to convert existing Per-Trunk Signaling (PTS) trunks to ISUP trunks.

CCITT7 ISUP Trunk Datafill for DMS-300

Nortel DMS-300 CCITT No. 7 signaling ISUP trunks have a signaling selector type of C7UP, a pulse type of SS7 with an external protocol of CCITT.

After table TRKSGRP is datafilled, table ISUPDEST must be datafilled to identify the routeset associated with the ISUP IBN trunk subgroup.  After table ISUPDEST is datafilled, trunks are added to table TRKMEM in the normal manner.  Table C7TRKMEM must be datafilled to associate the CCITT No. 7 signaling ISUP trunks with a circuit identification code.

Country Code CLI Prefix

The Calling Line Identity (CLI) is converted to an international format, or the CLI completely removed on outgoing international IBN7 or European Telecommunications Standards Institute Integrated Services Digital Network User Part (ETSI ISUP) routes.  The CLI is controlled by datafill on a TRKSGRP basis.

CLI refers to both the Originating Line Identity (OLI) and default CLIs.

The EDITCLI option triggers modification or removal of the CLI.  The option is only allowed on outgoing or two-way trunk types, and is rejected on incoming trunks.

Modification of the CLI results in the modification of the Calling Party Number (CPN) parameter in the Initial Address Message (IAM).  If the CLI is to be converted to an international format, the country code of the country where the switch is located (set by parameter NATIONAL_COUNTRY_CODE in table OFCENG [Office Engineering]), is prefixed to the CLI and the Nature Of Address (NOA) is set to International (INTL).  Because only one datafilled country code is supported, modification of the CLI to an international format is not supported when one switch terminates lines from multiple countries.  To modify the CLI, the NOA field of the CPN parameter must be set to National Significant Number (NSN), and the Numbering Plan Indicator (NPI) must be set to ISDN (Telephony) numbering plan (E164).

Removal of the CLI results in the CPN parameter not being included in the IAM, because it is an optional parameter.  The CLI is removed regardless of the NOA or NPI settings of the CPN parameter.

PRI: Location Indicators

The PRI: Location Indicators feature provides the actual location, the CAUSE location, for which the DMS-100 switch generates a CAUSE value.  The CAUSE value is the reason for the call failure.  The CAUSE location is the location at which the call failure occurs.

Feature AF7875 maps the CAUSE location values and provisions for Primary Rate Interface (PRI) NTNA and NTNI protocol variants.

Feature AF7585 provides the following functionalities, beginning with NA011:

The CAUSE location option, LOC_MAP, in the LOCATION field in table TRKSGRP is introduced, and provides the location mapping capability for the:

The location option, LOC_MAP, is the default value for PRI NTNI protocol variants.  For PRI NTNA, the location option needs to be provisioned.

Note:  The value LOC_MAP applies to the network side of the Customer Premises Equipment (CPE) to DMS-100 interface when the datafill for subfield IFCLASS in table TRKSGRP is NETWORK.

To activate this function, the datafill for the subfield LOCATION is LOC_MAP.

The CAUSE location is part of the CAUSE Information Element (IE) and is set based on where the CAUSE value occurs.  The CAUSE IE is the mechanism that reports CAUSE values and location indicators are sent within certain PRI messages to report diagnostic information to and from the CPE.  These PRI messages include disconnect, progress, release, release complete, and status messages.  The following table list the messages:

Error Messages That Contain CAUSE IE

Call Establishment Message        Description
PROGRESS                          Indicates interworking with non-ISDN or in-band information 
                                  as available.
Call Clearing Messages
DISCONNECT                        Call clearing request.

RELEASE                           Indicates the channel was disconnected and requests the 
                                  channel release and call reference release.

RELEASE COMPLETE                  Indicates that the channels and call reference are released.
Miscellaneous Message
STATUS                            Response to a status inquiry.

Information Specific to PRI with Semipermanent Packet

The PRI with Semipermanent Packet feature provides X.25 primary rate B-channel packet services to meet National ISDN-2 requirements.  This feature allows operating company personnel to assign a B-channel on the PRI T1 link from the CPE to the packet handler.  The existing X.25 services on BRI are available on PRI.

The SGRPVAR field can be datafilled with signaling type X.25.  Signaling type X.25 distinguishes PRI with Semipermanent Packet on PRI CLLI from other types of CLLIs.

Information Specific to Spectrum Peripheral Module

Table TRKSGRP provides an integer index to table SPMECAN (SPM Echo Canceller).  Thus, each trunk in table TRKSGRP can be associated to a tuple in table SPMECAN.  This is done by providing an option called SPMECIDX for SS7 trunks in table TRKSGRP.  The SPMECIDX option is used to reference an existing tuple in table SPMECAN and associate it with a PTS trunk subgroup.

This allows a trunk to be spread across a Digital Trunk Controller (DTC) and a SPM.  That is, some members in the trunk group are on a DTC, while other members of the same trunk group are on a SPM.  The members of a trunk group provisioned on a SPM use the SPMECIDX option, while members on the DTC use the ECSTAT field.

Note:  The existing functionality in table TRKSGRP that supports external and internal echo cancellers remains unchanged.

The following rules apply to table control for table TRKSGRP:

Beginning with SP13, Echo Cancellation (ECAN) functionality is available for NA100 applications.  ECAN functionality is supported for the following ISUP trunks in the NA100 market:

ECAN functionality is not supported for PTS and PRI trunks in the NA100 market.  Datafilling only supported trunks is enforced when trying to datafill SPMECDIX option in table TRKSGRP.  An attempt to datafill the SPMECDIX option for an unsupported trunk results in an error message that SPMECDIX is not allowed.

Datafill Sequence & Table Size

The following tables must be datafilled before table TRKSGRP:

The following universal translations route tables must be datafilled after table TRKSGRP:

If a tuple exists with the option ATPINDEX selected, the ATPIDX selected for that option is found in table ATPIES.

Fields CONTCHK and COTREQ must be datafilled on the BCS+1 side.  To transfer the data to the peripheral, Busy (BSY) and Return-To-Service (RTS) the Pulse Code Modulation 30 Digital Trunk Controller (PDTC).

The Enhanced Digital Carrier Module (DCME) option for C7UP trunks are only added or removed if there are no trunk members datafilled in the trunk group.  The trunk members can be datafilled after this option is set, and after table DCMEINV is datafilled.

In table TRKMEM, the following checks are present:

Table Size

The maximum number of trunk groups possible for each office is 8,191.

The number of trunk subgroups is equal to two times the number of trunk groups.  The maximum number of trunk subgroups that can be assigned is 16,382.

Table TRKSGRP can have up to two tuples in each tuple in table TRKGRP.

If the number of trunk subgroups is not equal to two times the number of trunk groups, the quantity is automatically adjusted by table control.

Memory for the number of trunk subgroups is set in field SIZE in table DATASIZE.  Field DATSKEY in table DATASIZE must be set to TRKSGRP.


The following table describes datafill for table TRKSGRP:

Table TRKSGRP Field Descriptions

Field       Subfield       Entry               Explanation and Action
SGRPKEY                    See Subfields       Subgroup Key
                                               This field consists of subfields CLLI and SGRP.

            CLLI           Alphanumeric        Common Language Location Identifier
	                   (1 to 16            Enter the Common Language Location Identifier 
			   characters)         (CLLI) code that is assigned in table CLLI to
			                       the trunk group to which the subgroup belongs.

            SGRP           Numeric             Subgroup Number
	                   (0 or 1)            Enter the number assigned to the trunk subgroup.
CARDCODE                   Alphanumeric        Card Code
                                               Enter a card code from the list of available 
SGRPVAR                    Alphanumeric        Signaling Data Selector 
                                               Enter a selector from the list of available

SGRPVAR                    See Subfield        Variable Subgroup Data
                                               This field consists of subfields SIGDATA and 
					       DIR, and subfields specific to the value in 
					       subfield DIR.

            SIGDATA                            Signaling Data
	                                       Enter one of the entries as detailed in the

            DIR                                Direction
	                                       Enter "IC", "OG", or "2W".

            ESUPR          F, H, or N          Echo Suppressor
	                                       Enter "N" (no) if the trunk subgroup is part of
					       a SPM PTS trunk group.

            OPTION         SPMECIDX            Option 
	                                       If this field contains the value SPMECIDX 
					       (SPM Echo Canceller Index), enter data to
					       subfield EC_IDX.

            EC_IDX         0 to 255            Echo Canceller Index 
	                                       Enter the value created for this trunk subgroup 
					       in table SPMECAN.  This associates the trunk 
					       subgroup with the required echo canceller in 
					       table SPMECAN.  Option SPMECIDX is used by C7UP-,
					       ISDN-, PTS-, STD- and TUP-signaled trunks, and 
					       specified ISUP trunks supervised by a SPM node. 
					       The index must exist in table SPMECAN before it 
					       is entered as datafill in table TRKSGRP.
ALL_NOA                                        All Natures of Address
                                               This trunk subgroup member can send and receive 
					       all values of NOA, including spares.
ALL_NPI                                        All Numbering Plan Indicators
                                               This trunk subgroup member can send and receive 
					       all values of NPI, including spares.

Datafill Example

The following example shows datafill for the PRI Location Indicators feature:

64K6DT0 0     DS1SIG    ISDN      20 20 87Q931 2 N STAND NETWORK PT_PT LOC_MAP N UNEQ 255 N 
                                  DEFAULT DTCI 0 10 24 64K HDLC (DTCI 0 12 24 64K HDLC) $ $

The following example shows datafill for PRI with Semipermanent Packet:

PKTPRI01 0    DS1SIG    X25

The following example shows datafill for SPM using PRI trunking:


Table TRKSGRP no longer requires a restart after datafill changes.  Activation is immediate.