1. Space Data Link Security Protocol Compatibility with other standards Bruno Saba DCT/TV/IN 26/10/2010

2. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 2 SDLSP Compatibility with other standards ■If we want compatibility, we cannot modify anything which is already defined  TM Frame Transfer Frame Primary Header Transfer Frame Secondary Header (Optional) Transfer Frame Data Field FECF (Opt.) OCF (Opt.) Transfer Frame Primary Header Transfer Frame Secondary Header (Optional) User Data Field Security Header Security Trailer  The Transfer Frame Data Field is the only field we have the right to modify, as its content is user defined (data…)  By doing this, no other service or standard will be impacted OCF (Opt.) FECF (Opt.)

3. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 3 SDLSP Compatibility with other standards ■If we want compatibility, we cannot insert a new field between two already defined  TM Frame  This is not compatible with TM Space Data Link Protocol standard (§4.1.6.1.1) Transfer Frame Primary Header Transfer Frame Secondary Header (Optional) User Data Field Security Header Security Trailer ■ The same applies to the AOS Frame OCF (Opt.) FECF (Opt.)

4. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 4 SDLSP Compatibility with other standards ■TC Data Frames Transfer Frame Primary Header Transfer Frame Data Field FECF (Opt.)  Acceptance Data (AD) or Bypass Data (BD) TC Frame (no segmentation) Transfer Frame Primary Header Security Header Security Trailer FECF (Opt.) User Data Field

5. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 5 SDLSP Compatibility with other standards ■TC Data Frames  Acceptance Data (AD) or Bypass Data (BD) TC Frame (segmentation used) Transfer Frame Primary Header Transfer Frame Data Field FECF (Opt.) Segment Header Transfer Frame Primary Header Security Header Security Trailer FECF (Opt.) Segment Header User Data Field

6. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 6 SDLSP Compatibility with other standards ■TC FARM Control Frames Transfer Frame Primary Header Control Command Information  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…) FECF (Opt.)  Bypass Control (BC) TC Frame (Control Command Flag set in Primary Header)

7. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 7 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 Transfer Frame Primary Header Security Header Security Trailer FECF (Opt.) Segment Header (Opt.) Transfer Frame Data Field (User Data)  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

8. Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 8 SDLSP Compatibility with other standards Thank you for your attention