90 likes | 240 Views
Space Data Link Security Protocol Compatibility with other standards. Bruno Saba DCT/TV/IN 26/10/2010. SDLSP Compatibility with other standards. If we want compatibility, we cannot modify anything which is already defined TM Frame. Transfer Frame Secondary Header (Optional). OCF
E N D
Space Data Link Security ProtocolCompatibility with other standards Bruno Saba DCT/TV/IN 26/10/2010
SDLSP Compatibility with other standards • If we want compatibility, we cannot modify anything which is already defined • TM Frame Transfer Frame Secondary Header (Optional) OCF (Opt.) FECF (Opt.) Transfer Frame Primary Header Transfer Frame Data Field • The Transfer Frame Data Field is the only field we have the right to modify, as its content is user defined (data…) Transfer Frame Secondary Header (Optional) Transfer Frame Primary Header Security Header Security Trailer OCF (Opt.) FECF (Opt.) User Data Field • By doing this, no other service or standard will be impacted Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010
SDLSP Compatibility with other standards • If we want compatibility, we cannot insert a new field between two already defined • TM Frame Transfer Frame Secondary Header (Optional) Transfer Frame Primary Header Security Header OCF (Opt.) Security Trailer FECF (Opt.) User Data Field • This is not compatible with TM Space Data Link Protocol standard (§4.1.6.1.1) • The same applies to the AOS Frame Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010
SDLSP Compatibility with other standards • TC Data Frames • Acceptance Data (AD) or Bypass Data (BD) TC Frame (no segmentation) Transfer Frame Primary Header FECF (Opt.) Transfer Frame Data Field Transfer Frame Primary Header Security Header Security Trailer FECF (Opt.) User Data Field Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010
SDLSP Compatibility with other standards • TC Data Frames • Acceptance Data (AD) or Bypass Data (BD) TC Frame (segmentation used) Segment Header Transfer Frame Primary Header FECF (Opt.) Transfer Frame Data Field Segment Header Security Header Transfer Frame Primary Header Security Trailer FECF (Opt.) User Data Field Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010
SDLSP Compatibility with other standards • TC FARM Control Frames • Bypass Control (BC) TC Frame (Control Command Flag set in Primary Header) Transfer Frame Primary Header Control Command Information FECF (Opt.) • Problem : Everything is defined ! No space left for inserting security fields… • Any attempt to insert a security field will void the compatibility with the TC Space Data Link Protocol • Question : do we really want to protect FARM control commands ? (if so, we will need to amend the TC SDLP standard…) Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010
SDLSP Compatibility with other standards • TC Frames : AD/BD and BC frames require different processing • For a given Global Virtual Channel, one can have AD and BD TC Frames Segment Header (Opt.) Security Header Transfer Frame Primary Header Transfer Frame Data Field (User Data) Security Trailer FECF (Opt.) • And for the same Global Virtual Channel, one can have BC TC Frames Transfer Frame Primary Header Control Command Information FECF (Opt.) • The on-board processing is different, and depends on the status of the Control Command Flag in the Frame Primary Header Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010
SDLSP Compatibility with other standards Thank you for your attention Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010