<?xml version="1.0" encoding="UTF-8"?>
<reference anchor="I-D.ietf-manet-nhdp-optimization" target="https://datatracker.ietf.org/doc/html/draft-ietf-manet-nhdp-optimization-04">
   <front>
      <title>An Optimization for the Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)</title>
      <author initials="C." surname="Dearlove" fullname="Christopher Dearlove">
         <organization>BAE Systems ATC</organization>
      </author>
      <author initials="T. H." surname="Clausen" fullname="Thomas H. Clausen">
         <organization>LIX, Ecole Polytechnique</organization>
      </author>
      <date month="January" day="23" year="2015" />
      <abstract>
	 <t>The link quality mechanism of the Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP) enables &quot;ignoring&quot; some 1-hop neighbors if the measured link quality from that 1-hop neighbor is below an acceptable threshold while still retaining the corresponding link information as acquired from the HELLO message exchange. This allows immediate reinstatement of the 1-hop neighbor if the link quality later improves sufficiently.

 NHDP also collects information about symmetric 2-hop neighbors. However, it specifies that if a link from a symmetric 1-hop neighbor ceases being symmetric, including while &quot;ignored&quot; (as described above), then corresponding symmetric 2-hop neighbors are removed. This may lead to symmetric 2-hop neighborhood information being permanently removed (until further HELLO messages are received) if the link quality of a symmetric 1-hop neighbor drops below the acceptable threshold, even if only for a moment.

 This specification updates RFC 6130 &quot;Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)&quot; and RFC 7181 &quot;The Optimized Link State Routing Protocol Version 2 (OLSRv2)&quot; to permit, as an option, retaining, but ignoring, symmetric 2-hop information when the link quality from the corresponding 1-hop neighbor drops below the acceptable threshold. This allows immediate reinstatement of the symmetric 2-hop neighbor if the link quality later improves sufficiently, thus making the symmetric 2-hop neighborhood more &quot;robust&quot;.
	 </t>
      </abstract>
   </front>
   <seriesInfo name="Internet-Draft" value="draft-ietf-manet-nhdp-optimization-04" />
   
</reference>
