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Re: [Question #232890]: tcp code project not decompress IP packet well


Question #232890 on rohc changed:

    Status: Open => Answered

Didier Barvaux proposed the following answer:

> I download the project code with TCP profile in a separate dev branch:
> https://code.launchpad.net/~didier-barvaux/+junk/rohc-tcp ,

The TCP profile is not merged in the main dev branch. The branch you
mention is now obsolete. I encourage you to use
https://code.launchpad.net/~didier-barvaux/rohc/main instead.

> then use it to compress and decompress the IP packets created by
> "Ping" ,however, it can not decompress some IP packets correctly,
> so make it time out.
> one of the input packets for decompression is : E634126B08003D5
> C03000D5C03000D006162636465666768696A6B6C6D6E6F707172
> 7374757677616263646566676869, which is the thirty-first ping
> packet and not decompressed rightly,can you see it ?

No, I cannot see it. The ROHC compression scheme does not compress one
single IP packet, but full streams of IP packets. I cannot analyze the
problem with one single packet. Even more if the packet is the
compressed ROHC packet.

You need to provide me the full stream of IP packets you try to
compress. Saying "ping" is not enough, every operating systems generate
different ping packets. You can provide me the information by sending me
(or making available for download) a network capture in PCAP format. Use
tcpdump or wireshark to create one. Try to compress it with
zip/gzip/bzip2 before sending it.

I'll also need the exact version of the ROHC library (X.Y.Z for
releases, revision number for dev versions).


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