Technical Summary:
MLE is a protocol for link-layer configuration, including link layer
addressing, transmit and receive modes, wake/sleep cycles and security.
Its use in ad hoc mesh networks is complementary to existing IETF
neighbor discovery protocols, such as IPv6 ND [RFC4861] and NHDP
[RFC6130]. MLE can be used to configure individual links and to
distribute configuration values that are shared across a network.
Per-link configuration uses one-hop messages with link-local addresses.
Network-wide configuration uses multicasts and requires some form of
multi-hop multicast forwarding. MLE resolves the issue of determining
two-way link quality between nodes in a lossy network (e.g. wireless) by
allowing a node to periodically multicast an estimate of the quality of
its links. This allows a node to determine if it has a usable link to a
neighbor without first configuring that link.
Working Group Summary:
Due to the general nature of the protocol and its application to link
layer technology, there was no particular WG which suited the draft. It
has been discussed in the 6lowpan and roll WG mailing lists. The only
controversy notable was the use of UDP as the base protocol for MLE.
Some suggested ICMPv6 would be more appropriate tied to RPL messages,
however this had the criticism of narrowing the scope of MLE, which has
been written without any specific IETF protocol in mind.
Document Quality:
There are numerous existing implementations of the protocol as it is
currently being adopted and tested by ZigBee Alliance members involved
in the development of the ZigBee IP stack. There are currently 7
independent vendors implemeting the protocol. Thomas Clausen has
performed a thorough review of draft version 02 and his comments have
been incorporated in version 03 onwards.
Personnel:
The Document Shepherd is Robert Cragie. The Responsible Area Director is
Ralph Droms.