8.1 Introduction to the TUP Layer

8.2 The TUP Configuration

8.3 Sample TUP Configuration File

8.4 TUP Configuration Parameters Reference

8.4.1 General Parameters

8.4.2 Service Access Point (SAP) Definition

8.4.3 Network Service Access Point (NSAP) Definition

8.4.4 Circuit/Group Definitions

8.1 Introduction to the TUP Layer

Like the ISUP layer, SS7 Telephone User Part (TUP) software provides an interface for applications to establish, maintain, and clear circuit switched connections via the SS7 network. The TUP layer is also responsible for circuit [group] management, such as blocking, unblocking, and resetting of circuits and circuit groups.

The SS7 TUP layer operates in accordance with the CCITT (ITU-T) recommendations Q.721-Q.724 and China GF001 - 9001 (Technical Specifications of SS7 for the National Telephone Network of China). TUP is not used in ANSI networks, so there is no applicable ANSI standard for TUP.

The configurable objects represented by the TUP layer are Circuits, User Service Access Points (User SAPs), and Network Service Access Points (NSAPs). In addition, the TUP layer has a set of general configuration parameters which define the behavior of the TUP layer as a whole.

Circuits are the physical bearer circuits controlled by the TUP layer. Like the ISUP layer, circuits are identified by both a circuit index and a circuit identification code (CIC). The circuit index is a number unique across all circuits configured on a particular TX board. This number has only local significance - it is used between the TUP layer and the local call processing application to identify a particular circuit.

The CIC (usually called the kick, or kick code) is used between signaling points (the SS7 TUP layer and the far exchange that terminates the other end of the circuit) to uniquely identify a particular circuit. The CIC must be configured at both ends of the circuit to identify the exact same bearer facility, for example, the same T1 span and timeslot. CICs need not be unique across circuits that terminate on different far exchanges.

Circuits are specified in the TUP configuration file in groups. A group is one or more circuits with contiguous circuit indexes and contiguous CICs that terminate on the same far exchange and have common characteristics. A single circuit group will frequently be used to represent all the timeslots on a single T1 or E1 span, for example. When defining a circuit group, only the circuit index and CIC of the first circuit in the group, along with the number of circuits in the group, are specified. The TUP layer derives the circuit index and CIC for subsequent circuits since they are considered to be contiguous. The starting circuit index and starting CIC for a group need not be the same value.

User SAPs define the interface between the TUP layer and the user applications.

Note: This release of the TUP layer supports only a single user application. Only one user SAP should be configured.

The NSAP defines the interface between the TUP layer and the MTP layer. It identifies the MTP network SAP to used by the TUP layer, allowing multiple user parts (TUP, ISUP, and SCCP) to share access to the MTP layer services. Figure 10 illustrates the concept of user SAPs and NSAPs:

Figure 10. TUP User SAPs and Network SAPs

8.2 The TUP Configuration

The SS7 distribution software contains a utility program, tupcfg, which reads a text configuration file and downloads the specified configuration to the TUP task on the TX board, typically as part of the download sequence.

The general format of the TUP configuration file is provided here:

<General Configuration Parameters>
<User SAP definition>
<SAP Parameters>
END
<NSAP definition>
<NSAP Parameters>
END
<Circuit Group 1 definition>
<Circuit Group Parameters>
END
<Circuit Group n definition>
<Circuit Group Parameters>
END

8.3 Sample TUP Configuration File

The TUP distribution software contains sample configuration files for both ITU-T and China configurations. These configurations may be used in conjunction with the MTP sample configuration files to test TUP applications using two TX boards in a back-to-back arrangement (see Chapter 3). The following example shows the sample ITU-T configuration file for one board:

#  TUP Configuration File
# General configuration parameters
MAX_SAPS             1
MAX_NSAPS            2
MAX_CIRCUITS         2048
MAX_GROUPS           16      !max number of circuit groups
MAX_DPCS             16      !max number of dest. point codes
MAX_ROUTES           10      !max number of routes
ALARM_LEVEL          2       !alarm level
TRACE_EVENT          NO      !turning on=YES/off=NO event tracing 
TRACE_DATA           NO      !turning on=YES/off=NO data tracing 
TIMER_TRACE          NO      !turning on=YES/off=NO timer tracing 
CHECKPOINT_TYPE      YES     !enable checkpointing from primary to backup
                             !this parameter is not required in 
                             !standalone mode
MTPPAUSE_TIMER       2       !MTP3 Pause timer started when pause is
                             !received from MTP3. On expiration, all of
                             !the configured circuits are cleaned up. 
                             !If it is set to zero, then this timer is
                             !disabled.
END
# Service Access Point (SAP)
USER_SAP             0
SWITCH_TYPE          ITU-T   !switch type (ITU-T, CHINA)
QCONGONSET1          64      !user queue congestion onset level 1
QCONGABATE1          32      !user queue congestion abatement level 1
QCONGONSET2          96      !user queue congestion onset level 2
QCONGONSET2          64      !user queue congestion abatement level 2
QCONGONSET3          128     !user queue congestion onset level 3
QCONGONSET3          96      !user queue congestion abatement level 3
END
# Network Service Access Point (NSAP)
NSAP                 0       !Network layer SAP Id
MTPSAP               0       !MTP layer SAP Id
SWITCH_TYPE          ITU-T   !switch type (ITU-T, CHINA)
OPC                  0x01    !my point code
SSF                  SSF_NAT !sub-service field value to use
END
#
# Circuit Database
CIRCUIT              1          !circuit number
CIC                  0          !circuit identification code
DPC                  0x02       !DPC of serving far exchange 
NUM_CIRCUITS         200        !number of circuits in this group
GROUP_ID             1
SWITCH_TYPE          ITU-T      !switch type (ITU-T, CHINA)
END
#
# Circuit Group 2
CIRCUIT              201        !circuit number
CIC                  200        !circuit identification code
DPC                  0x02       !DPC of serving stp
NUM_CIRCUITS         200        !number of circuits in this group
GROUP_ID             2
SWITCH_TYPE          ITU-T      !switch type (ITU-T, CHINA)
END
#
# Circuit Group 3
CIRCUIT              513        !circuit number
CIC                  513        !circuit identification code
DPC                  2          !DPC of serving stp
NUM_CIRCUITS         255        !number of circuits in this group
GROUP_ID             3
END
#
END                              # End TUP configuration

8.4 TUP Configuration Parameters Reference

There are five major sections of the TUP configuration file: general parameters, user SAP definition, network SAP definition, routes, and circuits.

8.4.1 General Parameters

The general parameters control the overall operation of the TUP layer process.

Parameter Name	Default	Range	Usage
MAX_SAPS	1	1	Defines the maximum number of user applications.
MAX_NSAPS	1	1	Defines the maximum number of interfaces with the MTP 3 network layer.
MAX_CIRCUITS	96	0 to 65535	The maximum number of circuits to be managed by the TUP layer.
MAX_GROUPS	32	0 to 65535	The maximum number of circuit groups managed by the TUP layer.
MAX_DPCS	16	1 to 256	Defines the maximum number of destination point codes configured.
ALARM_LEVEL	1	1 to 4	In order to limit the number of alarms to the more critical ones, set this number closer to 1.
TRACE_EVENT	NO	YES | NO	YES enables event tracing. NO disables event tracing.
TRACE_DATA	NO	YES | NO	YES enables data tracing. NO disables data tracing.
TIMER_TRACE	NO	YES | NO	YES enables timer tracing. NO disables timer tracing.
CHECKPOINT_TYPE	YES	YES | NO	Enables (YES) or disables (NO) checkpointing from primary to backup in redundancy mode. Note: This parameter is not required in standalone mode.
MTPPAUSE_TIMER	2	0 to 65535	Specifies the maximum duration of an MTP3 pausetimer before clearing circuits associated with a DPC. The MTP3 pause timer starts when a pause is received from MTP3. When the pause timer expires, all the configured circuits associated with the DPC for which the pause is received are cleaned up. Setting the timer value to 0 disables this functionality.
PC_FORMAT	DEFAULT	DEFAULT [DFLT], INTER-NATIONAL [INTL], JNTT	Point Codes are interpreted/displayed as 24-bit 8.8.8 values. Point Codes are interpreted/displayed as 14-bit 3.8.3 values. Point codes are interpreted/displayed as 16-bit mcode.scode.ucode values with the U-code in the most significant 7 bits, the S-code in the next 4 bits, and the M-code in the least significant 5 bits.
T20 _TIMER	5	0 to 65535	Time to wait to send the second confirming group reset signal.
T21_TIMER	15	0 to 65535	Time to wait for a response to circuit group reset signal (should be 4-15 seconds).
T22_ TIMER	60	0 to 65535	Time to wait to send another group reset signal.
T23_TIMER	5	0 to 65535	Time to wait to send the second confirming maintenance group block signal.
T24_TIMER	5	0 to 65535	Time to wait to send the second confirming maintenance group unblock signal.
T25_ TIMER	300	0 to 65535	Time to wait to alert maintenance group unblock signal.
T26_TIMER	15	0 to 65535	Time to wait for a response to maintenance group block signal (should be 4-15 seconds).
T27_TIMER	60	0 to 65535	Time to wait to send another maintenance group block signal.
T28_TIMER	15	0 to 65535	Time to wait for a response to maintenance group unblock signal (should be 4-15 seconds).
T29_TIMER	60	0 to 65535	Time to wait to send another maintenance group unblock signal.
T30_TIMER	5	0 to 65535	Time to wait to send the second confirming hardware failure group block signal.
T31_TIMER	5	0 to 65535	Time to wait to send the second confirming hardware failure group unblock signal.
T32_TIMER	15	0 to 65535	Time to wait for a response to hardware failure group block signal (should be 4-15 seconds).
T33_TIMER	60	0 to 65535	Time to wait to send another hardware failure group block signal.
T34_TIMER	15	0 to 65535	Time to wait for a response to hardware failure group unblock signal (should be 4-15 seconds).
T35_TIMER	60	0 to 65535	Time to wait to send another hardware failure group unblock signal.
T36_TIMER	5	0 to 65535	Time to wait to send the second confirming software group block signal.
T37_TIMER	5	0 to 65535	Time to wait to send the second confirming software group unblock signal.
T38_TIMER	15	0 to 65535	Time to wait for a response to software group block signal (should be 4-15 seconds).
T39_TIMER	60	0 to 65535	Time to wait to send another software group block signal.
T40_TIMER	15	0 to 65535	Time to wait for a response to software group unblock signal (should be 4-15 seconds).
T41_TIMER	60	0 to 65535	Time to wait to send another software group unblock signal.
END	N/A	N/A	Marks the end of the general section.

8.4.2 Service Access Point (SAP) Definition

The SAP definition defines the characteristics of the TUP service presented to the user application(s).

Note: This release of the TUP layer software allows for configuration of only a single TUP user SAP. Only one application may use the TUP service at a time.

Parameter Name	Default	Range	Usage
USER_SAP	none	0 to MAX_SAPS	SAP number.
SWITCH_TYPE	ITU-T	ITU-T, CHINA	The switch type (version of the TUP protocol employed for this application). Must match (one of) the switch type(s) defined in the NSAP definition section.
QCONGONSET1	32		User queue congestion onset level 1.
QCONGABATE1	16		User queue congestion abatement level 1.
QCONGONSET2	64		User queue congestion onset level 2.
QCONGABATE2	48		User queue congestion abatement level 2.
QCONGONSET3	96		User queue congestion onset level 3.
QCONGABATE3	80		User queue congestion abatement level 3.
END			Marks the end of the SAP section.

8.4.3 Network Service Access Point (NSAP) Definition

The NSAP definition defines the characteristics of the TUP interface to the MTP 3 layer.

Note: This release of the TUP layer software allows for configuration of only a single NSAP. Only one switch type may be handled at a time.

Parameter Name	Default	Range	Usage
NSAP	none		NSAP ID.
SWITCH_TYPE	ITU-T	ITU-T, CHINA	The switch type (that is, the version of the SS7 protocol employed for this MTP 3 interface). Must be either ITU-T or CHINA.
OPC	none	N/A	The Point Code of this node, specified as x.y.z (three bytes, decimal, separated by periods) or as a hexadecimal number (for example, 0xnnnnn).
SSF	SSF_NAT	SSF_INTL, SSF_SPARE, SSF_NAT, SSF_RES	The Sub-service field of the SIO in outgoing TUP packets.
MTPSAP	0	0 to MAX_NSAPS	The MTP SAP with which to bind.
END	N/A	N/A	Marks the end of the NSAP section.

8.4.4 Circuit/Group Definitions

The circuit set definitions specify the characteristics of each of the circuit sets to be managed by the TUP layer. This includes the circuit identification codes (CICs) and destination point code (DPC) at the other end of the circuits. One entry is made for each circuit set. Any set can be designated as a predefined group by adding a group number to this definition. A predefined group can more easily be reset, blocked and unblocked with the API or by the network.

Parameter Name	Default	Range	Usage
CIRCUIT	none	1 to 65535	The number of the first circuit in this set. Circuits in this set are numbered from this number to (this number + NUM_CIRCUITS-1). This range must be unique for all circuits defined. This number is used by the application and the TUP layer to identify circuits, but has no meaning to the far exchange.
CIC	0	0 to 4095	The circuit identification code (CIC) of the first circuit in this set. Circuits in this set are assigned CICs from this number to (this number + NUM_CIRCUITS-1). This number range must agree with the CICs assigned to this circuit set at the far exchange.
DPC	none	N/A	The destination point code that this circuit set connect to. Use dot notation (such as 2.45.76) or a hex number (such as 0x101).
GROUP_ID	0	0 to 65535	This is the group ID number to assign to this group of circuits. 0 designates these circuits as not being a group.
NSAP_ID	0	0 to MAX_NSAPS	Which NSAP to use for these circuits, this value should match an NSAP ID in the NSAP definition area.
SWITCH_TYPE	ITU-T	ITU-T, CHINA	The protocol variant employed for this MTP 3 interface.
NUM_CIRCUITS	1	1 to 255	The number of circuits in this circuit set.
T1_TIMER	15	0 to 65535	Time to wait for continuity or continuity failure signal (10-15 seconds).
T2_TIMER	30	0 to 65535	Time to wait for address complete signal (20-30 seconds).
T3_TIMER	15	0 to 65535	Time to wait for clear forward signal after sending unsuccessful signal (4-15 seconds).
T4_TIMER	15	0 to 65535	Time to wait for clear forward signal after sending call-failure signal (4-15 seconds).
T5_TIMER	60	0 to 65535	Time to stop sending call-failure signals.
T6_TIMER	15	0 to 65535	Time to wait for release guard signal (4-15 seconds).
T7_TIMER	60	0 to 65535	Time to stop sending clear forward signals.
T8_TIMER	2	0 to 65535	Time to wait for a backward check-tone (should not exceed 2 seconds).
T9_TIMER	5	0 to 65535	Time to delay start first-time continuity recheck (1-10 seconds).
T10_TIMER	180	0 to 65535	Time to delay for multiple re-tests of continuity (60-180 seconds).
T11_TIMER	60	0 to 65535	Time to wait to alert maintenance following initiation of blocking signal.
T12_TIMER	15	0 to 65535	Time to wait for response to blocking signal (4-15 seconds).
T13_TIMER	60	0 to 65535	Time to wait to alert maintenance that a response to the initial blocking signal is not received.
T14_TIMER	60	0 to 65535	Time to wait to repeat blocking signal.
T15_TIMER	15	0 to 65535	Time to wait for a response to an unblocking signal (4-15 seconds).
T16_TIMER	60	0 to 65535	Time to wait to alert maintenance that a response to the initial unblocking signal is not received.
T17_TIMER	60	0 to 65535	Time to wait to repeat unblocking response.
T18_TIMER	15	0 to 65535	Time to wait for a response to a reset-circuit signal (should be 4-15 seconds).
T19_TIMER	60	0 to 65535	Time to wait to send another reset-circuit signal.
END	N/A	N/A	Marks the end of this circuit group definition.