The implementation assumes that any RMPP request that requires a
response uses DS RMPP. Based on the RMPP start-up scenarios defined
by the spec, this should be a valid assumption. That is, there is no
start-up scenario defined where an RMPP request is followed by a
non-RMPP response. By having this assumption we avoid any API
changes.
In order for a node that supports DS RMPP to communicate with one that
does not, RMPP responses assume a new window size of 1 if a DS ACK has
not been received. (By DS ACK, I'm referring to the turn-around ACK
after the final ACK of the request.) This is a slight spec deviation,
but is necessary to allow communication with nodes that do not
generate the DS ACK. It also handles the case when a response is sent
after the request state has been discarded.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>