Alvaro, Sorry for the late response.
Please see below. > -----Original Message----- > From: Alvaro Retana (aretana) [mailto:[email protected]] > Sent: Monday, December 13, 2010 3:47 PM > To: Jeffrey (Zhaohui) Zhang > Cc: [email protected] > Subject: RE: [OSPF] OSPF Hybrid Broadcast and P2MP Interface Type > > > From: [email protected] [mailto:[email protected]] On Behalf > Of > > Jeffrey (Zhaohui) Zhang > > Jeffrey: > > Hi! > > ... > > It is difficult to go into too much details, but there are real > > examples of true-broadcast radio networks where the bw/delay is > > different between different pairs of radios. > > It is very tempting to use the model that you describe, but radio > networks can be "flimsy" because of interference, signal fading, > movement, etc.. The broadcast model for neighbor > discovery/maintenance > can quickly become unusable for nodes that loose connectivity > to the DR. > It is very easy to see how the same L2 media may provide nodes that > don't have the same view of the other nodes (not everyone is within > radio range of everyone else, for example). There are real-life examples where a radio network is built to guarantee that if a node can reach a central node then it can reach others who can also reach the central node (e.g., a satellite network). A node's transimission/receiving capability can be impacted by its placement, but the broadcast property of the network is still maintained (if a station is so out of place then it is considered off the network, just like a cable is cut in the wired ethernet case). The premise is that we have a broadcast network but one can reach some stations with a metric that is different from when reaching others. If that premise is not satisfied, then it's a different topic (and out of the scope). Thanks. Jeffrey > > This brings me to wanting to establish p2p adjacencies while using the > broadcast capabilities of the media to reach whoever is within > transmission range (to propagate Hellos and to flood LSAs). The > recognition that the characteristics between nodes can be different > should also result in the recognition that the adjacencies > between pairs > of nodes may not all have the same state at the same time. > > My 1c. > > Alvaro. > > _______________________________________________ OSPF mailing list [email protected] https://www.ietf.org/mailman/listinfo/ospf
