rohc team mailing list archive

["Wong, Tak - 0665 - MITLL" <Tak.Wong@xxxxxxxxxx>]

Didier:

   I used your new code in the main branch, and set the list_trans_nr to 5, 10, 25, 50, respectively, but I am still getting these errors, and as many PAWS
drops at the TCP layer:

[  675.415623] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.415626] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.415639] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.415641] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.417085] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.417089] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.417112] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.417116] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.417574] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/rnd_8 (code = -5)
[  675.417578] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.417635] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/rnd_8 (code = -5)
[  675.417639] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.417658] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/rnd_8 (code = -5)
[  675.417662] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.417694] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/rnd_8 (code = -5)
[  675.417698] rohc_mod(5218):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.421835] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.421838] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.421861] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.421864] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.421875] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.421878] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.422860] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.422863] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5
[  675.422875] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1702 d_decode_header()] failed to decompress packet TCP/seq_8 (code = -5)
[  675.422877] rohc_mod(5225):   [ERROR] [/home/vamuser/iphc-kernel/rohc/decomp/rohc_decomp.c:1726 d_decode_header()] status -5







-----Original Message-----
From: Rohc [mailto:rohc-bounces+tak.wong=ll.mit.edu@xxxxxxxxxxxxxxxxxxx] On Behalf Of Didier Barvaux
Sent: Sunday, April 27, 2014 12:36 PM
To: rohc@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Rohc] ROHC TCP dynamic field changes

Hello,

> > Will sending these packets first eliminate the problem?   I think
> > there are still chances the inconsistent list struct will occur.
> 
> I think that the current library sends only one single
> co_common/seq_8/rnd_8 packet when the list of TCP options changes its 
> structure. If that packet is lost, the structure change is lost as 
> well.
> 
> To circumvent this, the ROHC protocol requires that the compressor 
> sends the changes until it is confident enough that the decompressor 
> got the changes.
> 
> So, one packet is not enough. It is not robust enough to packet loss 
> or reordering. It should be sent N times at least. N shall be 
> configurable because it depends on network type and conditions.

I have just implemented the repetition of the list in case of change.
It is available in the main branch at revision  or later.

You may configure the number of transmissions of the list with the
rohc_comp_set_list_trans_nr() function. See its documentation:
http://rohc-lib.org/doc/rohc-doc-r1027/group__rohc__comp.html#ga32608bc06e1b0d1656e463eeb1ccbd7f

Tell me if it corrects the problems you encounter.

Regards,
Didier