- Basic Route Maintenance procedure:
- Each message hop is
reliable:
- Each frame must be acknowledged (just like IEEE 802.11)
Example:
- When B receives
a frame from
A:
B must send back an ACK:
- If no acknowledgement is
received:
The message will be re-transmitted up to a maximum number of retries....
- If a message
is unsuccessful
after
the maximum number
of retransmissions:
- A node
transmits a
ROUTE ERROR message
to the
original sender
of the packet
- The ROUTE ERROR message contains the failed link
Example:
- A node
transmits a
ROUTE ERROR message
to the
original sender
of the packet
- When a source node receives a
route error message:
- The source node will
delete the
source route from the
route cache
(The source node will also save the broken link is a link cache for future use)
Example:
- The source node will
delete the
source route from the
route cache
- The source node will
try to
transmit the
again:
- If the source node has
another (different) source route
that does not contain
the failed link:
- Use source routing to send the message
- Invoke the
Route Discovery procedure to
- Find a route to the destination node.....
- If the source node has
another (different) source route
that does not contain
the failed link:
- Each message hop is
reliable: