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problem with H225. Bad asn1 file ?

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Hello

I try to send a message coded in H225 in asn1 (my message is generated with the Binary Note Encoder librairie). I used the ans1 file h2250v7.asn link to download it

Wireshark don't understand my message and I got malformed packet error.

Which version is used by Wireshark to decode h225 message ?

asked 01 Sep '11, 09:48

Guillaume%20Ansquer's gravatar image

Guillaume An...
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2 Answers:

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Hi, The verios is -- Taken from ITU ASN.1 database -- http://www.itu.int/ITU-T/formal-language/itu-t/h/h225-0/2009/H323-MESSAGES.asn Did you use PER encoding?

answered 01 Sep '11, 22:28

Anders's gravatar image

Anders ♦
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Thanks for this document.

It's looks similar than the one I use. I use PER encoding.

Maybe my problem is the "...," in the asn1 file. My compiler for generating java source don't want them so I suppress them. What is the use of them in asn1 ?

(exemple:

H323-UU-PDU ::= SEQUENCE { h323-message-body CHOICE {setup Setup-UUIE,
callProceeding CallProceeding-UUIE,
connect Connect-UUIE, alerting Alerting-UUIE,
information Information-UUIE,
releaseComplete ReleaseComplete-UUIE, facility Facility-UUIE,
...,
progress Progress-UUIE,
empty NULL, -- used when a Facility message is sent,--

This answer is marked "community wiki".

answered 02 Sep '11, 01:21

Guillaume%20Ansquer's gravatar image

Guillaume An...
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That may very well be your problem, you may want to check with X.690 but without looking at the spec, "...," means that the SEQUENCE may be extended, if that is the case there is an extension bit set and other encoding details.

(02 Sep '11, 07:20) Anders ♦