Canon FAX-L1000 - Manual (Page 510)

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FAX-L1000 Chapter 5: Appendix
•How to View the Dch dump list
a) Title Column
*1: Date and Time.
*2: Elapsed time since the power was turned ON (msec.). Increases every 5 msec..
*3: Message direction.
TX> : The message the machine sent
: The message the network sent
*4: Message Name. “ (L2) ” shows that the message is a Layer 2 message.
*5: Message’s parameter. Displayed as hexadecimal numbers, 2 numbers of one octet each.
b) D-channel Layer 2 Messages
The D-channel Layer 2 message (SABME, UA, etc.) is not shown in the Dch dump list. It
shows messages processed inside the machine.
• EST REQ : Machine sends SABME message
• EST CNF : The UA message is received from the network pertaining to the SABME
message which was sent by the machine
• EST IND : The UA message is sent from the machine pertaining to the SABME message
received by the network
• REL REQ : Machine sends a DISC message
• REL CNF : The UA message is received from the network pertaining to the DISC message
sent by the machine
• REL IND : The UA message is sent from the machine pertaining to the DISC message
received from the network. Additionally, depending on the cause for the removal of ISDN
line, even when Layer 2 has been disconnected, the main message is still shown.
c) D-channel Layer 3 Message and Information Element
Normally, 4-octets of header information are attached to a D-channel Layer 3 message. (*6)
The length of the header information varies according to the value of the 2nd octet. For
example, when the value of the 2nd octet is “00,” the header information length is 3 octets,
and when then value of the 2nd octet is “01,” the header information length is 4 octets. The
information elements will be displayed following the header information. (*7)
There are 2 types of information element: single octet information element and variable
length information element.
c-1) Single Octet Information Elements
The Sending Complete information element which is included in the SETUP message can
be used by this machine. The
service data #4B ISDN BASIC Bitswitch SW06 bit0 is
set to “1,” and when there is an outgoing call, on the Dch dump list right after the header
information in the SETUP message sent by this machine, the main information is shown,
and “
A1 ” is set.