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<TITLE>Re: [Sls-slp] Restrictions on Services within TM</TITLE>
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<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Greg, B) and D) are there because they are exclusive. In other words you can’t have Packet service and VCA service on the same VC but I too don’t understand the other restrictions.<BR>
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On 7/23/09 10:38 AM, "Kazz, Greg J (313B)" <greg.j.kazz@jpl.nasa.gov> wrote:<BR>
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</SPAN></FONT><BLOCKQUOTE><FONT SIZE="5"><FONT FACE="Arial"><SPAN STYLE='font-size:16.0px'>All,<BR>
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Can any of you help provide the rationale as to why these restrictions on services in the current CCSDS TM Space Data Link Protocol book exist? I am having a difficult time in trying to come up with such a rationale. Perhaps these restrictions are no longer valid?<BR>
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The text below is copied from section 2.2.4 of the current CCSDS TM Space Data Link Protocol book:<BR>
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Restrictions on Services<BR>
There are some restrictions on the services provided on a Physical Channel:<BR>
a) if the Master Channel Frame Service exists on a Master Channel, other<BR>
services shall not exist simultaneously on that Master Channel;<BR>
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b) on one Master Channel, the Virtual Channel Operational Control Field<BR>
Service shall not exist simultaneously with the Master Channel Operational Control Field Service;<BR>
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c) if the Virtual Channel Frame Service exists on a Virtual Channel,<BR>
other services shall not exist simultaneously on that Virtual Channel;<BR>
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d) on one Virtual Channel, the Virtual Channel Packet (VCP) Service shall<BR>
not exist simultaneously with the Virtual Channel Access Service.<BR>
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thanks and best regards,<BR>
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Greg Kazz<BR>
Chairman CCSDS SLS-SLP WG<BR>
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