Sending SMS with UDH using Kannel

zohar_amir
zohar_amir used Ask the Experts™
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I'm using Kannel GW to send/receive SMS messages. The messages should be addressed to a certain 16-bit port, thus I'm trying to send the messages with the following UDH: "X-Kannel-UDH: 05040E06FDE8". This didn't work for some reason (the receiving application did not respond), so I sent it from one Kannel GW to another. On the receiving Kannel i got "X-Kannel-UDH: 040E06FDE8". As you can see, it seems that the IEI got "chopped off". Any idea why and how ? How can I use this correctly, so it works (the UDH that I send is the one that I get, I guess...) ?
Thanks.
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Commented:
I haven't used Kannel, but I have had a quick look through the docs.  What you seem to be doing looks OK.  Can you post the code that you use to create the message (just the part where you write the UDH should do to start with).

How do you prepare the UDH value?

I can't make any promises, but I'll help if I can ;-)

Author

Commented:
I use a python script to connect to the kannel, via HTTP. The headers look like this:

headers = {"Content-type": "text/plain",
           "X-Kannel-UDH": "05040E06FDE8",
           "X-Kannel-To": "+12345678",
           "X-Kannel-Username": "bla",
           "X-Kannel-Password": "bli"}

Commented:
Well I have almost no knowledge of python, but what you have there seems to define everything OK.  How do you decode the message at the other end?
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Author

Commented:
looked in the kannel's logs (smsbox)

Commented:
Sorry zohar_amir,  I didn't realise that last comment was from you.  I thought it was a question from someone else :-(

I don't know enough about the way Kannel works to really help here.  Not knowing python doesn't help much either :-(

My best suggestion at this stage is that you search or post on the following site:

http://www.mail-archive.com/devel@kannel.org/
I found the reason 2 days ago (i was too bussy to update you).
The problem was that the UDHL was missing. I should have added "06" at the beginning (there are 6 octets in "05040E06FDE8"). When I use "X-Kannel-UDH: 0605040E06FDE8" it all works fine.
For some reason I thought kannel adds this by itself (not very difficult...), but now I know it doesn't...
Thanks for the effort.

Commented:
Doh!

That was one of the things I thought of, but I was assuming that this was prepended somewhere else in the python script.

;-)

As long as you've fixed it, just post in CS to have the question deleted and your points refunded ;-)

Author

Commented:
I assumed _kannel_ adds this automatically... we think too much...

Commented:
;-)

Author

Commented:
again, thanks for the effort.

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