+ - On some network models (L07, CM02, LV08), an implicit loopback link is created
+ for local communication. Default bandwidth was 500MBps and latency was 15µs,
+ which was rather bad. Default values have been changed to 10GBps and 0 latency.
+ Options network/loopback-lat and network/loopback-bw have been added to adapt
+ these values if needed. Network and routing models already providing separate
+ loopbacks (clusters and such) are not impacted by this change.