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<P><FONT color=#0000ff size=2>Greg et al,</FONT></P>
<P><FONT size=2><FONT color=#0000ff>Apologies for the late response. Here
are my thoughts on this:<BR></FONT><BR>>>APPROVE WITH CONDITIONS: 1
(33.33%) (Durst)<BR>>><BR>>>In section 2.2, it is unclear what the
conformance requirements<BR>>>are. There are two protocols (Space
Packet and Encapsulation Packet)<BR>>>under a single service
interface. Are both required for conformance?<BR>><BR>>**Both
protocols can be used to encapsulate other protocols.<BR>>For
example,<BR>>CFDP can be encapsulated into space packets by using
APID=2045<BR>>or into an<BR>>Encapsulation packet by using PID = '110'. I
need to know more<BR>>about what<BR>>you are expecting in terms of
"conformance requirements". The<BR>>encapsulation<BR>>service specifies
the inputs, what protocols are used to do the<BR>>encapsulating, and
references the Space Link Identifiers<BR>>document, which<BR>>supplies all
of the IDs one needs in order to carry out the service.**<BR><BR><FONT
color=#0000ff>The conformance requirements I am asking about are whether
an<BR>implementation is "conformant" if it only implements one of these<BR>two
protocols (SPP or Encapsulation Packet). If so, please say so.<BR>If not,
please explain how you ensure interoperability between two<BR>conformant
applications that invoke this service (when, for example,<BR>one is hosted on a
node that implements SPP and the other is hosted<BR>on a node that implements
only Encapsulation). <BR></FONT><BR>>>The document requires a SANA
Implications section to address<BR>>registered<BR>>>APIDs and PIDs, and
to define procedures to register new<BR>>APIDs and PIDs.<BR>><BR>>**
All of the IDs used by the Encapsulation Service are defined in the<BR>>Space
Link Identifiers spec. This is true for all of the link layer<BR>>protocols.
Therefore, it is the Space Link Identifiers book<BR>>that requires
a<BR>>SANA implication section, not Encap. service. APIDs and
PIDs<BR>>are defined<BR>>in the Space Link Identifiers book which is
referenced in<BR>>section 2.3 **<BR><BR><FONT color=#0000ff>OK. Does
the Space Link Identifiers book have such a section? My<BR>comment will be
successfully resolved if either of these documents has a<BR>SANA
section.<BR></FONT><BR><BR>>>The document requires a security implications
section.<BR>><BR>>** I will work with Howie on how to accomplish this
**<BR><BR><FONT color=#0000ff>OK. When added, this comment will be
resolved.<BR></FONT><BR>>>Section 3.3.2.2: It is unclear to me
whether and how a user of the<BR>>>service is expected to know the correct
GVCID and PVN to use.<BR>> Are these<BR>>>statically assigned?
Assigned on a per-mission basis? What are the<BR>>>implications on
interoperability?<BR>><BR>>** GVCID = SCID + VCID. SCID is statically
assigned. VCID is<BR>>an enterprise<BR>>or project managed parameter.
CCSDS recognizes certain PVNs.<BR>>All of these<BR>>IDs are defined and
their values are listed (if not a managed<BR>>parameter) in<BR>>the Space
Link Identifiers spec. For things like PVN it's very<BR>>static.
For<BR>>APIDs, an enterprise has to really manage these across
the<BR>>enterprise in<BR>>order for interoperability to happen. Global
enterprise APIDs begin to<BR>>happen in these cases. **<BR><BR><FONT
color=#0000ff>This explanation is helpful. I know that the book is
normative, rather than informative, but it would be nice to have this explained
in there.<BR></FONT><BR>>>Section 4.1, item b) the APID "shall be
one of the reserved APIDs"<BR>>>defined in reference [8]. Are there
guidelines or further<BR>>restrictions on<BR>>>how a particular APID is
chosen? Does interoperability<BR>>depend on
this<BR>>>choice? In Table 5-2 of reference [8], there appear to
be<BR>>two degrees of<BR>>>"reserved" -- reserved and assigned to a
particular protocol,<BR>>and reserved<BR>>>but unassigned. Are
any of these fair game? Or was it intended that<BR>>>these be drawn
from the 2040-2044 range?<BR>><BR>>** Again APIDs are a managed parameter
by an enterprise except<BR>>for the ones<BR>>defined in the CCSDS Space
Link Identifiers book. There are no further<BR>>restrictions except the ones
managed by the enterprise. Yes,<BR>>interoperability is an issue for the
management of those apids. It is<BR>>intended that 2040-2044 be used for
encapsulation by space packets. **<BR><BR><FONT color=#0000ff>Could you please
clarify these points in the document?<BR><BR>I think that it would be useful to
summarize the "managed parameters" somewhere, to make it clear specifically what
bilateral agreements are required to ensure interoperability. This may be
part of the "lore" within the CCSDS community, but if we want other folks to use
this, making it clear what needs to be agreed upon out-of-band seems
important.<BR></FONT><BR>>>Section 4.2.2.1, item g -- this is a poorly
worded summary of section<BR>>>4.2.2.8. Recommend rewording to
"Packet Length (0, 1, 2, or<BR>>4 octets) --<BR>>>See Figure
4-2.<BR>><BR>>** Agreed. It will be changed to Packet Length (0, 1, 2, or
4<BR>>octets). **<BR><BR><FONT
color=#0000ff>Thanks</FONT>.<BR><BR>>>Section 4.2.2.3 -- "The value
'110'..." does this require a<BR>>RID against<BR>>>135.0-B-2 (or
whatever)?<BR>><BR>>** The PID value '110" needs to be added to Space
Link<BR>>Identifiers blue<BR>>book via a new pink sheet **<BR><BR><FONT
color=#0000ff>OK, thanks. <BR></FONT><BR>>>Section 4.2.2.6 -- "The
extended protocol IDs..." I didn't<BR>>see this in<BR>>>reference
[8]. Does it require a RID?<BR>><BR>>** A new table called "Extended
Protocol IDs" needs to be added to the<BR>>Space Link Identifiers blue book
via the new pink sheet. **<BR><BR><FONT
color=#0000ff>OK.<BR></FONT><BR>>>As a note to the secretariat, I'd
suggest that we add an<BR>>Annex for red<BR>>>books that require
modifications to other documents that consolidates<BR>>>and
summarizes those external dependencies. ** I agree **<BR><BR><FONT
color=#0000ff>Perhaps also another annex that summarizes the "managed
parameters" that the protocol specifies that must be agreed among peers in order
to ensure interoperability?<BR><BR>Thanks, and again, sorry for the
delay.<BR><BR>Bob</FONT></FONT><FONT color=#0000ff> </FONT></P></BODY></HTML>