Question #229419 on rohc changed: https://answers.launchpad.net/rohc/+question/229419
Wei Wang gave more information on the question: Hi Didier, It seems the problem is the UDP checksum bytes. I just copied the values from the IP headers. After I changed them to 0, I can see many compressed packet sizes are 19, which means, 40 header bytes are compressed to 3 bytes, great!! Still need your confirm this result is expected. However, another problem rises. The decompressed packet size is negative. There is an error line in log. [ERROR] [d_generic.c:3508 d_generic_decode()] non-IR packet (2) received in No Context state Here is a part of log: [rohc_comp.c:564 rohc_compress()] ROHC size = 19 (feedback = 0, header = 3, payload = 16), output buffer size = 2048 ROHC packet resulting from the ROHC compression: 0x54 0x00 0x00 0x0c 0x3e 0x8e 0x4a 0x69 0x52 0x1b 0xfa 0x02 0xe0 0xb0 0x37 0x9f 0xd8 0x74 0x10 [rohc_decomp.c:420 rohc_decompress()] decompress the 19-byte packet #26 [rohc_decomp.c:1636 d_decode_feedback_first()] skip 0 byte(s) of padding [rohc_decomp.c:1568 rohc_decomp_decode_cid()] no add-CID found, CID defaults to 0 [rohc_decomp.c:727 d_decode_header()] ROHC packet is not an IR packet [rohc_decomp.c:742 d_decode_header()] context with CID 0 found [d_generic.c:3501 d_generic_decode()] decode packet as 'UO-0' [ERROR] [d_generic.c:3508 d_generic_decode()] non-IR packet (2) received in No Context state [rohc_decomp.c:434 rohc_decompress()] state in decompressor = 1 [rohc_decomp.c:923 d_optimistic_feedback()] send a STATIC NACK feedback [feedback.c:76 f_feedback2()] FEEDBACK-2: first 4 bits = 0xa0 (ACK type = 2, mode = 2) [feedback.c:92 f_feedback2()] FEEDBACK-2: transmit SN = 0x0000b951 on 20 bits (12 bits in base header, 8 bits in SN option) [feedback.c:96 f_feedback2()] FEEDBACK-2: 4 bits of SN = 0x0 [feedback.c:98 f_feedback2()] FEEDBACK-2: 8 bits of SN = 0xb9 [feedback.c:107 f_feedback2()] FEEDBACK-2: 8 bits of SN option = 0x51 [feedback.c:387 f_wrap_feedback()] add CRC option to feedback [rohc_comp.c:1149 c_piggyback_feedback()] try to add 6 byte(s) of feedback to the next outgoing ROHC packet [rohc_comp.c:1181 c_piggyback_feedback()] 6 byte(s) of feedback added to the next outgoing ROHC packet decompression of fake IP packet failed. decompressed size = -5 -- You received this question notification because you are a member of ROHC Team, which is an answer contact for rohc. _______________________________________________ Mailing list: https://launchpad.net/~rohc Post to : [email protected] Unsubscribe : https://launchpad.net/~rohc More help : https://help.launchpad.net/ListHelp
