Protocol-control information

In <a href="/facts/Telecommunications/vxoj1cxR">telecommunications</a>, the term protocol-control information (PCI) has the following meanings:

<ol><li>The queries and replies among <a href="/facts/Communication/EGEkchsT">communications</a> equipment to determine the respective capabilities of each end of the communications <a href="/facts/Data_link/fSNk5Nus">link</a>.</li>
<li>For layered systems, <a href="/facts/Information/3LdrzXtJ">information</a> exchanged between entities of a given layer, via the service provided by the next lower layer, to coordinate their joint operation.</li></ol>

This article incorporates <a href="/facts/Copyright_status_of_works_by_the_federal_government_of_the_United_States/Q1jvr96g">public domain material</a> from <a href="https://web.archive.org/web/20220122224547/https://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm">Federal Standard 1037C</a>. <a href="/facts/General_Services_Administration/Np3opv9x">General Services Administration</a>. Archived from <a href="https://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm">the original</a> on 2022-01-22.

Protocol-control information open-in-new

Protocol-control information