Data delivery in NDN Routing plane stays the same for now but data plane has state and in charge now Monitor the performance Detect problems at the data plane quickly k Explore multiple alternative paths Routing plane is now a helper, i. e it's useful but doesn't have to be perfect * E.g, prefix hijack, link failure, congestion NDN Retreat May 2011
Data Delivery in NDN Routing plane stays the same for now but data plane has state and in charge now. Monitor the performance. Detect problems at the data plane quickly Explore multiple alternative paths Routing plane is now a helper, i.e., it’s useful but doesn’t have to be perfect. E.g., prefix hijack, link failure, congestion. May 2011 NDN Retreat 26
Overview of Forwarding Strategy Forwarding strategy is to determine which face to use to forward an interest Basic process k Faces are ranked In general, try higher ranked face(s)first * If data return within a reasonable time update rtt otherwise, try next face(s) Different strategies may make different choices Ranking is dynamically adjusted Details are work in progress NDN Retreat May 2011
Overview of Forwarding Strategy Forwarding strategy is to determine which face to use to forward an interest. Basic process: Faces are ranked In general, try higher ranked face(s) first If data return within a reasonable time, update RTT. Otherwise, try next face(s). Different strategies may make different choices. Ranking is dynamically adjusted. Details are work in progress. May 2011 NDN Retreat 27
Ranking Faces The factors Routing provides the initial and basic information Forwarding preference, e. g inter-As peer relationship etc Performance metrics k Throughput, loss rate, rtt, etc The specific design we simulated Faces are labeled Green(working), Yellow(may work), Red(not working), based on whether data come back Within each class, ordered by routing preference NDN Retreat May 2011 28
Ranking Faces The factors Routing provides the initial and basic information. Forwarding preference, e.g., inter-AS peer relationship, etc. Performance metrics Throughput, loss rate, RTT, etc. The specific design we simulated Faces are labeled Green (working), Yellow (may work), Red (not working), based on whether data come back. Within each class, ordered by routing preference. May 2011 NDN Retreat 28
Choosing Faces When no faults, i. e, data return as expected Use the highest ranked face, but periodically probe other faces by sending interests over Or, spread the interests over multiple faces When data dont come back after expected rtt E.g., hijack, link failure, congestion, etc. nDN can keep trying different faces without worrying about loops What we simulated Round-robin based on the ran king Retransmission plus round-robin Flooding each face also enforce an interest limit It is available for forwarding only if there' s room for more interests NDN Retreat May 2011
Choosing Faces When no faults, i.e., data return as expected Use the highest ranked face, but periodically probe other faces by sending interests over. Or, spread the interests over multiple faces. When data don’t come back after expected RTT E.g., hijack, link failure, congestion, etc. NDN can keep trying different faces without worrying about loops. What we simulated: Round-robin based on the ranking Retransmission plus round-robin Flooding Each face also enforce an interest limit It is available for forwarding only if there’s room for more interests. May 2011 NDN Retreat 29
Interest return When a node cannot satisfy an interest, it returns the interest to the previous hop k data are acKs. while returned interests are NACKs k With error code to indicate the reason Pro: the downstream node learns the problem quicker and more explicitly k RTt-based timeout is conservative to avoid false alarms k Con an extra mechanism NDN Retreat May 2011 30
Interest Return When a node cannot satisfy an interest, it returns the interest to the previous hop data are ACKs, while returned interests are NACKs. With error code to indicate the reason Pro: the downstream node learns the problem quicker and more explicitly. RTT-based timeout is conservative to avoid false alarms Con: an extra mechanism May 2011 NDN Retreat 30