On Nov 19, 2003, at 10:47 AM, Paul Higgs (CA/EUS) wrote:
I have found a problem with the dissector for H245 in regards to
displaying the signalType of a UserInputIndication. The signalType
prints as a ? when it is actually an !
H.225.0 CS
H323_UserInformation
H323_UU_PDU
h323_message_body
h323_message_body: .... .110 : facility (6)
FacilityUUIE
ProtocolIdentifier: 0.0.8.2250.0.4
FacilityReason
transportedInformation
CallIdentifier
guid: 2AFA51A97C0000102143204166275475
multipleCalls: 0... .... False
maintainConnection: 0... .... False
h245Tunneling: 1... .... True
h245Control
Item 0
Octet String Length: 7
H.245
MultimediaSystemControlMessage
PDU Type: .11. .... : Indication (3)
IndicationMessage
Indication Type: .... 1101 :
UserInputIndication (13)
UserInputIndication
signal
UserInputIndication_signal
signalType: ?
duration: 400
0000 00 80 37 84 fb 9c 00 10 b5 75 ac 1d 08 00 45 00
..7......u....E.
0010 00 6a bb 17 40 00 80 06 93 e7 c0 a8 15 32 c0 a8
.j..@........2..
0020 15 0c 75 5a 0f a1 e5 77 18 df 95 c4 e6 f4 50 18
..uZ...w......P.
0030 43 3a b0 d2 00 00 03 00 00 42 08 02 12 76 62 1c
C:.......B...vb.
0040 00 7e 00 34 05 26 80 06 00 08 91 4a 00 04 86 01
.~.4.&.....J....
0050 00 1f 01 80 11 00 2a fa 51 a9 7c 00 00 10 21 43
......*.Q.|...!C
0060 20 41 66 27 54 75 01 00 01 00 10 c0 01 80 09 01
Af'Tu..........
0070 07 6d 81 04 44 20 01 8f .m..D ..
I looked in the codebase and it seems that this element is not
dissceted as an IA5string but with some other method.
It's dissected as a restricted character string - but the set of
characters in that string includes "!".
What does the H.245 spec say that element is? And, if it's a
restricted character string:
1) what's the alphabet for it?
2) what's the numerical value of the first (and only) character in it)?
According to
http://www.packetizer.com/iptel/h245/h245_asn.html
the ASN.1 for it is
signalType
IA5String(SIZE (1) ^ FROM ("0123456789#*ABCD!")),
but the alphabet string passed to
"dissect_per_restricted_character_string()" is "!#*0123456789ABCD".
