This is our old Q&A Site. Please post any new questions and answers at

Hi !

I cannot explain myself the following case.

The SubmitSM packet was sent directly in one session (using Java application) making even socket flush after, but when I examine it in a Wireshark, I can see last 4 bytes (74203430) displayed, but not marked as part of the SubmitSM. However, they are marked as the begining of the next SMPP packet (Unbind). That's why the SMPP server cannot decode properly Unbind, since the first 4 bytes are wrong. Within the application log, I can see proper byte stream to be sent on the stream (including missing last 4 bytes) Do we have a problem with Tcp stack as Java is not dealing with Windows etc, just puts stream to the system Tcp stack ?

asked 08 Feb '14, 03:23

Miskulinko's gravatar image

accept rate: 0%

It looks like the Length field of the SMPP is incorrect: in frame 9 if you expand the SMPP tree you can see that it is 678 bytes. If you click on the SMPP line in the protocol-tree (middle) frame you'll see in the bottom status line that Wireshark thinks the SMPP is 678 bytes long but in the hex (bottom) pane you'll see this does not include the final 4 bytes.

So: the sender has a problem. It needs to include those final 4 bytes in the smpp length field.

permanent link

answered 10 Feb '14, 08:27

JeffMorriss's gravatar image

JeffMorriss ♦
accept rate: 27%

Uh, ive checked several times, but was concentrated on payload tlv length which is correct (630), not the header length :) Thx

(10 Feb '14, 09:15) Miskulinko
Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text]( "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 08 Feb '14, 03:23

question was seen: 1,766 times

last updated: 10 Feb '14, 09:15

p​o​w​e​r​e​d by O​S​Q​A