From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cirse-smtp-out.extra.cea.fr (cirse-smtp-out.extra.cea.fr [132.167.192.148]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id BA5F73B2A4 for ; Thu, 29 Feb 2024 08:23:03 -0500 (EST) Received: from pisaure.intra.cea.fr (pisaure.intra.cea.fr [132.166.88.21]) by cirse-sys.extra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 41TDN1pm045745; Thu, 29 Feb 2024 14:23:01 +0100 Received: from pisaure.intra.cea.fr (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id 5994020590B; Thu, 29 Feb 2024 14:23:01 +0100 (CET) Received: from muguet1-smtp-out.intra.cea.fr (muguet1-smtp-out.intra.cea.fr [132.166.192.12]) by pisaure.intra.cea.fr (Postfix) with ESMTP id 4BD9120591F; Thu, 29 Feb 2024 14:23:01 +0100 (CET) Received: from [10.8.32.70] (is156570.intra.cea.fr [10.8.32.70]) by muguet1-sys.intra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 41TDN1md061817; Thu, 29 Feb 2024 14:23:01 +0100 Message-ID: <0419d8c6-0c27-45e5-b0ab-495f3f758102@gmail.com> Date: Thu, 29 Feb 2024 14:23:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: fr To: Tomaso.deCola@dlr.de Cc: starlink@lists.bufferbloat.net References: From: Alexandre Petrescu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CEA-Virus: SOPHOS_SAVI_ERROR_OLD_VIRUS_DATA Subject: Re: [Starlink] space packet protocol document X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Feb 2024 13:23:04 -0000 Le 28/02/2024 à 19:53, Tomaso.deCola@dlr.de a écrit : > But there exists already a CCSDS spec for IP over CCSDS… > Moreover the snapshot you attached is about TC frames, I.e. for telecommand services… If they gave another example of non telecommand services, or if they told that IPv6 must not be carried in telecommand services... But I will wait and see for some time. Alex > > Tomaso > Sent from my iPhone > >> On 28. Feb 2024, at 18:47, Alexandre Petrescu via Starlink wrote: >> >> The CCSDS spec is an interesting document. >> >> I am trying to find a packet dump of a CCSDS packet that travelled in space according to this CCSDS spec. If there is a place with CCSDS packet dumps I am interested to see them. >> >> Given that, I could think about writing an IPv6-over-CCSDS preliminary Internet Draft. >> >> I could find a png image of a packet dump at ESA (https://essr.esa.int/project/ccsds-wireshark-dissector), but that is not a real packet dump binary file that could be loaded in wireshark; strangely, they do provide a dissector, but not a packet. >> >> Here are my IPv6 comments about CCSDS, relative to that png of a CCSDS packet (png attached): >> >>> - the shown 'Frame Length' field is on 16bits. For IPv6, this can be fine, in principle. The good thing is that the minimum MTU of IPv6 is 1280, and that can be encoded ok with a 16bit length field. On another hand, the 'Payload Length' of IPv6 is also on 16bit. This means that the largest normal IPv6 packet would not fit into a single CCSDS frame, and would need to be fragmented by CCSDS. Maybe fragmentation is little desirable when RTT is 45minutes. And, there are also the IPv6 'jumbograms'. >>> >>> - there is a 'Spacecraft ID' and 'VC ID' fields combined on 16bits: this field could be used, if appropriate in some context, to help with forming IPv6 link-local addresses. If there is worry about privacy, and these IDs could be used to input hashes, such as to obtain hopefully unique numbers; these hopefully unique numbers are often necessary when designing IPv6 addressing architectures, subnet numbers, IPv6 ULA addresses, secure addresses for secure identification, and similar. >>> >>> - there is a 'SDLS Header' containing a 'Security Parameter Index' field. If this packet contains an IPv6 packet with an ESP header (encapsulated sec'y protocol) then that too has a 'Security Parameter Index' field (SPI). It would be good to re-use. Ideally, one would rely entirely on IPsec and almost not at all on CCSDS-specific security. >> Alex >> >>> Le 23/02/2024 à 19:03, Dave Taht via Starlink a écrit : >>> Given the trouble the moon lander has had communicating, I looked over >>> this just now. >>> >>> https://public.ccsds.org/Pubs/133x0b2e1.pdf >>> >>> I reviewed a similar document for the earth-moon corridor by NASA >>> about 2 years ago, and it was a mess of non-interoperable bands and >>> protocols. I cannot remember the name of that one. >> >> _______________________________________________ >> Starlink mailing list >> Starlink@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/starlink