Welltech Dialogic SS7 Protocols ISUP - Manual (Page 88)

Section 6 Interface to Application
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6.7.4 Custom Parameter
The custom parameter is not defined by ITU-T or ANSI. It is a proprietary
parameter which is used for sending and receiving user defined parameters
between the user and the network in either direction. The user defined
parameter is encapsulated inside this special parameter which is reserved for
this purpose. The encapsulated user defined parameter is encoded as it would
appear in a message received from the network in name-length-data format.
Figure 5. Format of the Custom Parameter
8 7 6 5 4 3 2 1
Name = 00010100 (20)
Length = 3 – 255
1 Parameter name (as received from network)
2 Length of parameter (ie ‘Length – 2)
3 First octet of data (message type)
4 Second octet of data
:
n Last octet of data
6.7.5 Message Data
The message data parameter is not defined by ITU-T or ANSI. It is a
proprietary parameter which is used to convey whole messages transparently
between the user and the network in either direction. The data contained in
the parameter commences with the message type octet and continues with
the data in the exact format that it is conveyed to the network.
Figure 6. Format of the Message Data Parameter
8 7 6 5 4 3 2 1
Name = 11111010 (250)
Length = 1 – 255
1 First octet of data (message type)
2 Second octet of data
:
n Last octet of data
This parameter is used by ISUP to convey whole messages transparently
(e.g. PAM, ‘Generic’ CRG and unrecognized messages).
Pass Along message
The message data parameter may be used by ISUP to signal the content of a
received Pass Along Message to the user (the ISPXGOP_TRAN_PAM circuit
group option must be set).