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<title>Re: [Sls-slp] RE: TC commanding</title>
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<p class=MsoPlainText><i><span style='color:#548DD4'>Peter wrote:<o:p></o:p></span></i></p>
<p class=MsoPlainText><span style='color:#548DD4'>> Actually, according to
the definition of "Network Layer" in the ISO BRM, 7498, <o:p></o:p></span></p>
<p class=MsoPlainText><span style='color:#548DD4'>> the SPP is NOT a network
layer service since it does not exhibit most of the <o:p></o:p></span></p>
<p class=MsoPlainText><span style='color:#548DD4'>> properties defined in a
network layer. ……<o:p></o:p></span></p>
<p class=MsoPlainText><span style='color:#548DD4'>> Accordingly the SPP
should either be:<o:p></o:p></span></p>
<p class=MsoPlainText><span style='color:#548DD4'>> A) Treated as the
application layer data structure that it actually is, or<o:p></o:p></span></p>
<p class=MsoPlainText><span style='color:#548DD4'>> B) Be redefined and
extended to include all of the attributes that a true network layer service
must have.<o:p></o:p></span></p>
<p class=MsoPlainText><span style='color:#548DD4'>> Doing A) makes sense.</span>
<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>Absolutely right. The SPP is an Application layer
protocol and should remain as such. We have actually tied to use it as an Application
support service (APID, length delimitation, sequence are of significance to the
application), as a Transport service (sequence count), as a Network service (“Path
ID”) and as a Link multiplexing service (APID = link port ID, length
delimitation). As a consequence we have over-used and under-specified it. It’s
time to run it as an Application service over underlying Transport, Network and
Link services.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>In the Forward Space Packet configuration, the SPP runs
over SLE and IP as its Transport and Network layers in order to get to the
space Link terminus. If there is then just a single hop into space, this sort
of works. However, if there is more than one hop then the SPP is “naked”
and can’t go any further without a Network layer. So why don’t we
just get it over with and put one in for <i>all</i> SPP data transfers??<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>///a<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
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