XUDT UDT Conversion Feature

This feature provides for the conversion of these SCCP messages.

An XUDT(S) message to a UDT(S) message
A UDT(S) message to an XUDT(S) message

The conversion is performed on a service module card if the message was generated by the EAGLE, or on a LIM receiving the message if the message is MTP-routed. The conversion takes place just before the message is sent to the LIM that will be transmitting the message out of the EAGLE.

An SCCP Class 1 message that requires SCCP processing is processed by a service module card and then sent back to the receiving LIM to maintain sequencing. Message routing and the XUDT(S) UDT(S) conversion is performed on the receiving LIM in this case.

To configure the EAGLE to perform the XUDT UDT Conversion, these entities must be configured in the database.

The XUDT UDT Conversion feature must be enabled and turned on – perform the Activating the XUDT UDT Conversion Feature procedure.

Configure the destination point code of the XUDT(S) or UDT(S) message using either the ent-dstn or chg-dstn commands and specifying the sccpmsgcnv parameter. Perform one of these procedures in Database Administration – SS7 User's Guide.

Adding a Destination Point Code
Adding a Cluster Point Code
Adding a Network routing Point Code
Changing a Destination Point Code
Changing the Attributes of a Cluster Point Code

Table 2-24 shows the values of the sccpmsgcnv parameter.

Table 2-24 SCCPMSGCNV Parameter Values

SCCPMSGCNV Parameter Value	Parameter Description
NONE	No conversion is performed on messages for the destination. This is the default value of the `sccpmsgcnv` parameter if the `sccpmsgcnv` parameter is not specified with the `ent-dstn` command.
SXUDT2UDT	All segmented XUDT(S) and non-segmented XUDT messages for the destination are converted to UDT(S) messages.
XUDT2UDT	All non-segmented XUDT(S) messages for the destination are converted to UDT(S) messages. Segmented XUDT(S) messages are be converted to UDT(S) messages. All non-segmented XUDT(S) messages for the destination are converted to UDT(S) messages. Segmented XUDT(S) messages are not converted.
UDT2XUDT	All UDT(S) messages are converted to XUDT(S) messages.

UDT(S) to XUDT(S) Conversion

When converting a UDT(S) message to an XUDT(S) message, the changes shown in Table 2-25 are made to the message.

If the SCCP portion of the pre-converted message is longer that 270 bytes and the conversion results in the addition of the Hop Counter (1 byte) and Pointer to Optional Parameters (1 byte) fields causing the size of the SCCP portion to increase beyond a length of 272 bytes, then the segmentation of the message is not performed

Table 2-25 Parameter Values after UDT to XUDT or UDTS to XUDTS Conversion

UDT to XUDT Conversion		UDTS to XUDTS Conversion
Parameter	Value after UDT to XUDT Conversion	Parameter	Value after UDTS to XUDTS Conversion
Message Type	XUDT (0x11)	Message Type	XUDTS (0x12)
Protocol Class	Same as the pre-converted message.	Return Cause	Same as the pre-converted message.
Hop Counter	15, which is the maximum value.	Hop Counter	15, which is the maximum value.
Pointer to Called Party Address (CDPA)	Incremented from the pre-converted UDT message value by the size of the Pointer to Optional Parameters value (1 byte).	Pointer to Called Party Address (CDPA)	Incremented from the pre-converted UDTS message value by the size of the Pointer to Optional Parameters value (1 byte).
Pointer to Calling Party Address (CGPA)	Incremented from the pre-converted UDT message value by the size of the Pointer to Optional Parameters value (1 byte).	Pointer to Calling Party Address (CGPA)	Incremented from the pre-converted UDTS message value by the size of the Pointer to Optional Parameters value (1 byte).
Pointer to Data	Incremented from the pre-converted UDT message value by the size of the Pointer to Optional Parameters value (1 byte).	Pointer to Data	Incremented from the pre-converted UDTS message value by the size of the Pointer to Optional Parameters value (1 byte).
Pointer to Optional Parameters	0, since no optional parameters are present in a converted XUDT message.	Pointer to Optional Parameters	0, since no optional parameters are present in a converted XUDTS message.
Called Party Address (CDPA) Parameter	Same as the pre-converted message.	Called Party Address (CDPA) Parameter	Same as the pre-converted message.
Calling Party Address (CGPA) Parameter	Same as the pre-converted message.	Calling Party Address (CGPA) Parameter	Same as the pre-converted message.
Data	Same as the pre-converted message.	Data	Same as the pre-converted message.

XUDT(S) to UDT(S) conversion

When converting an XUDT(S) message to a UDT(S) message, the changes shown in Table 2-26 are made to the message.

If the sccpmsgcnv value for the destination is xudt2udt, only non-segmented XUDT(S) messages are converted to UDT(S) messages while segmented XUDT(S) messages, that is, messages that contain the Segmentation parameter are routed to the destination without being converted.

If the sccpmsgcnv value for the destination is sxudt2udt, both segmented and non-segmented XUDT(S) messages are converted to UDT(S) messages.

Table 2-26 Parameter Values after XUDT to UDT or XUDTS to UDTS Conversion

Feature Interactions

STP/LAN

Database Transport Access - DTA

Integrated Sentinel/IMF

ANSI/ITU SCCP Conversion

GTT Actions

Even though messages are selected for copying for the STP/LAN feature according to their received, non-converted values, the actual messages that are copied will have been converted since the flag for the STP/LAN feature is set on the incoming signaling link and the actual copy occurs on the outgoing signaling link. This applies to all MTP-routed and SCCP messages that are generated by the EAGLE.

The XUDT UDT Conversion feature does not affect the DTA feature’s functioning. The wrapper message is converted while the encapsulated message, which resides in the wrapper’s data area, is not converted. The destination has to extract and convert the encapsulated message if it wishes to route the encapsulated message back to the EAGLE.

Incoming messages are selected for copying according to their received, non-converted values. Outgoing messages are selected for copying according to their converted values. This applies to both MTP-routed and SCCP messages that are generated by the EAGLE.

The XUDT UDT Conversion feature is applied to MTP-routed SCCP messages that do not reach the service module cards before they are processed by the ANSI/ITU SCCP Conversion feature. For GT-routed messages and MTP-routed SCCP messages that are processed on the service module cards, the XUDT UDT conversion feature is applied after the ANSI/ITU SCCP conversion feature is performed on the message.

The XUDT UDT Conversion feature is applied after the GTT Actions have been performed on the message. This means that if 4 DUPLICATE GTT actions are performed on the message, the XUDT UDT conversion feature is applied separately on all of the duplicated messages.

XUDT to UDT Conversion		XUDTS to UDTS Conversion
Parameter	Value after XUDT to UDT Conversion	Parameter	Value after XUDTS to UDTS Conversion
Message Type	UDT (0x09)	Message Type	UDTS (0x0a)
Protocol Class	Same as the pre-converted message.	Return Cause	Same as the pre-converted message.
Hop Counter	Dropped from the converted message.	Hop Counter	Dropped from the converted message.
Pointer to Called Party Address (CDPA)	Decremented from the pre-converted (XUDT) message value by the size of the Pointer to Optional Parameters value (1 byte).	Pointer to Called Party Address (CDPA)	Decremented from the pre-converted (XUDTS) message value by the size of the Pointer to Optional Parameters value (1 byte).
Pointer to Calling Party Address (CGPA)	Decremented from the pre-converted (XUDT) message value by the size of the Pointer to Optional Parameters value (1 byte).	Pointer to Calling Party Address (CGPA)	Decremented from the pre-converted (XUDTS) message value by the size of the Pointer to Optional Parameters value (1 byte).
Pointer to Data	Decremented from the pre-converted (XUDT) message value by the size of the Pointer to Optional Parameters value (1 byte).	Pointer to Data	Decremented from the pre-converted (XUDTS) message value by the size of the Pointer to Optional Parameters value (1 byte).
Pointer to Optional Parameters	Dropped from the converted message.	Pointer to Optional Parameters	Dropped from the converted message.
Called Party Address (CDPA) Parameter	Same as the pre-converted message.	Called Party Address (CDPA) Parameter	Same as the pre-converted message.
Calling Party Address (CGPA) Parameter	Same as the pre-converted message.	Calling Party Address (CGPA) Parameter	Same as the pre-converted message.
Data	Same as the pre-converted message.	Data	Same as the pre-converted message.
Segmentation – applies only to a segmented ANSI/ITU XUDT message.	Dropped from the converted message.	Segmentation – applies to a segmented ANSI/ITU XUDTS message.	Dropped from the converted message.
Importance – applies only to an ITU XUDT message.	Dropped from the converted message.	Importance – applies only to an ITU XUDTS message.	Dropped from the converted message.
INS – applies only to an ANSI XUDT message.	Dropped from the converted message.	INS – applies only to an ANSI XUDTS message.	Dropped from the converted message.
MTI – applies only to an ANSI XUDT message.	Dropped from the converted message.	MTI – applies only to an ANSI XUDTS message.	Dropped from the converted message.
End of Optional Parameters	Dropped from the converted message.	End of Optional Parameters	Dropped from the converted message.