  UNIX X.25 questions? 
 The Question is:
 
Hi,
 
Could you please forward this question to someone who has experience in
Digital Unix and X.25, I am sure for them this question will be quite
straightforward to answer.
 
I have an interworking problem between an Ericsson Telephone exchange and a
Digital server used as a Billing Centre. We are trying to transfer files
using the FTAM protocol. Unfortunately I cannot give you more specifics on
the Digital server used, if thi
s *IS* necessary I can get it for you.
 
I work for Ericsson as the supplier of the telephone exchange, however we
are having difficulties working with the other company to trouble shoot the
situation due to language problems (Chinese).
 
 
The problem is at the X.25 level,
 
We send the following Connection message:
 
- - - - - - - - - - - - - - - - Frame 11 - - - - - - - - - - - - - - - - -
 
SUMMARY  Delta T     Destination   Source        Summary
 
Sniffer Network Analyzer data from 23-Dec-98 at 18:14:48, file a:eric1c.SYC,
Page 4
 
 
    11   48.9753  8861707001      8861708001       X.25 00F Call Req
Called:8861707001 Calling:8861708001
 
X.25: ----- X.25 Packet Level -----
X.25:
X.25: General format id = 10
X.25:         0... .... = Address bit (non-TOA/NPI address)
X.25:         .0.. .... = Delivery confirmation bit
X.25:         ..01 .... = Sequence numbering modulo 8
X.25:         .... 0000 = Logical channel group number = 0
X.25: Logical channel number = 0F
X.25: Packet type identifier = 0B (Call request)
X.25: Address length field = AA
X.25:            1010 .... = Calling DTE address length = 10 digits
X.25:            .... 1010 = Called  DTE address length = 10 digits
X.25: Called  DTE address = 8861707001
X.25: Calling DTE address = 8861708001
X.25: Facility length = 0
X.25:
 
 
We then receive back from the Digital server:
 
- - - - - - - - - - - - - - - - Frame 13 - - - - - - - - - - - - - - - - -
 
SUMMARY  Delta T     Destination   Source        Summary
    13    0.0058  8861708001      8861707001       X.25 00F Clr Ind DTE
originated
 
X.25: ----- X.25 Packet Level -----
X.25:
X.25: General format id = 10
X.25:         0... .... = Address bit (non-TOA/NPI address)
X.25:         ..01 .... = Sequence numbering modulo 8
X.25:         .... 0000 = Logical channel group number = 0
X.25: Logical channel number = 0F
X.25: Packet type identifier = 13 (Clear indication)
X.25: Clearing cause = 00 (DTE originated)
X.25: Diagnostic = 80 (IMP is unavailable)
X.25:
 
My first question is the meaning of the Diagnostic value 80 (Hex) - This is
a proprietry Digital value. If we send a protocol identifier in the message
then we receive Diagnostic value E8 (Hex). If you can tell me the meaning of
these two codes, that woul
d go a long way to solving our problems.
 
We then compared our situation to a working one. The following is a
connection request from an affiliated company:
 
- - - - - - - - - - - - - - - - Frame 1835 - - - - - - - - - - - - - - - - -
 
SUMMARY  Delta T     Destination   Source        Summary
  1835    2.3532  660055          0270451212       X.25 001 Inc Call
Called:660055 Calling:0270451212 Facils=3 ISO_TP
 
X.25: ----- X.25 Packet Level -----
X.25:
X.25: General format id = 10
X.25:         0... .... = Address bit (non-TOA/NPI address)
X.25:         .0.. .... = Delivery confirmation bit
X.25:         ..01 .... = Sequence numbering modulo 8
X.25:         .... 0000 = Logical channel group number = 0
X.25: Logical channel number = 01
X.25: Packet type identifier = 0B (Incoming call)
X.25: Address length field = A6
X.25:            1010 .... = Calling DTE address length = 10 digits
X.25:            .... 0110 = Called  DTE address length = 6 digits
X.25: Called  DTE address = 660055
 
Sniffer Network Analyzer data from 23-Dec-98 at 12:00:34, unsaved capture
data, Page 694
 
 
X.25: Calling DTE address = 0270451212
X.25: Facility length = 8
X.25: Facility code = 02 (Basic throughput class negotiation)
X.25: Facility parameter = AA
X.25:          1010 .... = Throughput of called  DTE = 9600 b/s
X.25:          .... 1010 = Throughput of calling DTE = 9600 b/s
X.25: Facility code = 42 (Packet size negotiation)
X.25: Packet size of called  DTE = 2048
X.25: Packet size of calling DTE = 2048
X.25: Facility code = 43 (Window size negotiation)
X.25: Window size of called  DTE = 2
X.25: Window size of calling DTE = 2
X.25: Protocol identification = 03010100 (ISO_TP)
X.25:
X.25: [4 bytes of user data = 03010100]
X.25:
 
ADDR  HEX                                                ASCII
0000  03 A8 10 01 0B A6 66 00  55 02 70 45 12 12 08 02  .(...&amp;f.U.pE....
0010  AA 42 0B 0B 43 02 02 03  01 01 00                 *B..C......
 
The response from the Digital server was:
 
- - - - - - - - - - - - - - - - Frame 1836 - - - - - - - - - - - - - - - - -
 
SUMMARY  Delta T     Destination   Source        Summary
  1836    0.0030  0270451212      660055           X.25 001 Call Acc
Facils=2
 
X.25: ----- X.25 Packet Level -----
X.25:
X.25: General format id = 10
X.25:         0... .... = Address bit (non-TOA/NPI address)
X.25:         .0.. .... = Delivery confirmation bit
X.25:         ..01 .... = Sequence numbering modulo 8
X.25:         .... 0000 = Logical channel group number = 0
X.25: Logical channel number = 01
X.25: Packet type identifier = 0F (Call accepted)
X.25: Address length field = 00
X.25:            0000 .... = Calling DTE address length = 0 digits
X.25:            .... 0000 = Called  DTE address length = 0 digits
X.25: Facility length = 6
X.25: Facility code = 42 (Packet size negotiation)
X.25: Packet size of called  DTE = 128
X.25: Packet size of calling DTE = 128
X.25: Facility code = 43 (Window size negotiation)
X.25: Window size of called  DTE = 2
X.25: Window size of calling DTE = 2
X.25:
 
ADDR  HEX                                                ASCII
0000  01 AA 10 01 0F 00 06 42  07 07 43 02 02           .*.....B..C..
 
Sniffer Network Analyzer data from 23-Dec-98 at 12:00:34, unsaved capture
data, Page 695
 
 
There are two main differences between this connection request message and
the one sent by the Ericsson exchange, it has a protocol identifier, and
facility information. When we have the Ericsson system send the protocol
identifier, then the Diagnostic ch
anges to E8 (Hex). However the Ericsson system is not capable of sending
facility information.
 
My second question is, can you disable the check in your system so that
facility information is not needed. If so can you give me some guidelines on
how to do this or where I can find out.
 
Your answers to these questions are greatly appreciated.
 
Kind regards,
David Morrison.
Ericsson Taiwan.
 
 
 The Answer is:
 
  Please contact the Compaq customer support center.
 
