What about addresses? Addresses are limited to local links No need for addresses that are globally unique, globally reachable, and abundant in supply w The new universal interconnection layer is named data IP eventually becomes a link layer protocol
16 What about addresses? Addresses are limited to local links No need for addresses that are globally unique, globally reachable, and abundant in supply. The new universal interconnection layer is “named data”. IP eventually becomes a link layer protocol
Receiver-driven data retrieval Consumer sends an interest carrying the name of the data that it wants to receive Routers forwards the interest towards the producer, and remembers the incoming interface of the interest The producer sends the data back. The data takes the exact reverse path of the interest to reach the consumer Data consumes Interests on the way back routers also cache the data as it arrives 17
17 Receiver-driven data retrieval Consumer sends an interest carrying the name of the data that it wants to receive. Routers forwards the interest towards the producer, and remembers the incoming interface of the interest. The producer sends the data back. The data takes the exact reverse path of the interest to reach the consumer. Data consumes Interests on the way back. Routers also cache the data as it arrives
ndN node Content store Face o /parc.com/videos/widgetampg/v3/50.. Index Pending Interest Table(PIT) ptr type Requesting Face 1 Prefix /parc. com/videos/WidgetA. mpg/v3/s1 0 C=Content store P=PIT Face FIB F=FIB 2 Prefix Face list Application /parc. com 0, 1 18
18 NDN node
NDN packet processing Interest Content Pending Interest FIB Store Table(PIT) forward Data X add incoming face return or drop the Interest Downstream Upstream forward Pending interest. Data cache Table(PIT) Content Store discard data X lookup miss v lookup hit NDN Retreat May 2011
NDN packet processing May 2011 NDN Retreat 19
Interest Forwarding ndn doesn 't loop Each Interest has a random number, nonce, to prevent looping Data follows Interest's trail, so Data doesnt loop either Thus ndn can use multiple paths better than IP k the extreme is to flood an interest and data will come back. IP would have to flood the data too Lots of choices in where to forward a particular interest: the forwarding strategy more details and evaluation later 20
20 Interest Forwarding NDN doesn’t loop. Each Interest has a random number, nonce, to prevent looping. Data follows Interest’s trail, so Data doesn’t loop either. Thus NDN can use multiple paths better than IP. the extreme is to flood an interest, and data will come back. IP would have to flood the data too. Lots of choices in where to forward a particular interest: the forwarding strategy. More details and evaluation later