[net2-wg] Network level names and mapping

[Rodrigo Fonseca]

Hi,

Om an I had a long chat yesterday about how to deal with the mapping
of names for the network layer and the link layer.

We want to provide a separation between network-level names (a unique
identifier per node), from link level names ("interfaces", radios, or
mac-addresses are examples). The motivating example is a node with two
radios, which will look like two links at the link layer, but will be
one network level entity, the node.

So far in TinyOS these have been clumped together as the TOS_LOCAL_ADDRESS.

That said, the link estimator will only care about link layer
addresses. These are the addresses you send active messages to, your
one-hop neighbor addresses. However, the network layer (in our case
for now the TreeRoutingEngine) will want to keep mappings of network
layer names. To keep that mapping, it will need two things:

1. a node will add its own network level name in its outgoing hello
messages, say nw_addr.
1.5 upon receiving this message, the network layer component at the
other node will know which nw_addr this message came from.

2. to establish the mapping between nw_addr and link level addresses
(ll_addr), upon receiving such a packet, the node will have to query
the entity it received it from for the link level source address.

The way we thought this should be done is the following. The Receive
interface for the TreeRoutingEngine is provided by the
LinkEstimatorReceiver. This module should also provide a LinkSrcPacket
interface, which would return the ll_addr for this packet.

Does this sound reasonable?
Thanks,
Rodrigo