[Sis-csi] IP Header Compression

[Scott,Keith L.]

Yes, we need to look at this.  'Standard' (vj) header compression relies on getting a first full-size header through, then compressing the rest (not so good for the emergency command scenario).

Scps-np would be a good alternative, with managed path identifiers for emergencies being just 1-2 byes.

  --keith


-----Original Message-----
From: sis-csi-bounces at mailman.ccsds.org <sis-csi-bounces at mailman.ccsds.org>
To: sis-csi at mailman.ccsds.org <sis-csi at mailman.ccsds.org>
Sent: Thu Sep 01 13:10:34 2005
Subject: [Sis-csi] IP Header Compression

I was curious about thoughts as to if and where we would address IP header compression in the Green Book.  On some our missions (and I think this is typical at least in deep space), if we have a reset of the system, the spacecraft may come up in an emergency mode of receiving 10 bps.  Hence, every bit is quite valuable at this point.  With a CCSDS header, we're looking at 6 bytes (plus a couple of bytes if a secondary header is used).  If we move to IPv6, this becomes 40.  At 10 bps, that's an additional uplink time of 25-26 seconds before a command can be received which is long enough to envision some nightmare scenarios.  Clearly IP header compression would alleviate this concern but I'm not sure where it fits or if it is needed in this doc (I hope I didn't miss it somewhere).

Chris