Next Step In Signaling (NSIS) and Internet Routing Dynamics Charles Shen and Henning Columbia University in the City of New York Internet Routing Dynamics Analysis Route prevalence and persistence - single dominant route - significant site to site variation - adaptive approach for NSIS Different types of route changes - wide scales in time or location - majority no change of hop count - route splitting and load balancing Measurement accuracy - 10-min fixed vs. 2-hour exp. - may capture the same changes - may miss half of the changes. - still site-to-site variation Impact of multi-homing - AS level route changes - Asymmetric routing Project Description  As part of the IETF NSIS working group, we are standardizing a protocol for signaling information about a data flow along its path in the Internet.  The protocol supports various signaling applications, such as Quality of Service (QoS) and Network Address Translation (NAT) and Firewall traversal.  The protocol design adopts a two-layer approach, a lower layer for transport, and an upper layer specific to each signaling application.  We are looking specifically at the signaling transport layer, or Generic Internet Messaging Protocol for Signaling (GIMPS) as well as its interaction with IP routing.  We conducted Internet routing dynamics measurement and evaluated route change detection methods in typical NSIS deployment models. End to end Routing Measurement Traceroute for path characterization 24 Public servers located in US, Iceland, Netherlands, Australia, Germany, Switzerland, Bulgaria, Sweden and Thailand. Both independent, exponential interval (15/30 min per site) and fixed interval (10 min per path) sampling Between April and August DS Client NSIS Deployment Models and the TTL Monitoring Method AS model: a central NE in each AS Entry model: ingress routers are NEs Border model: both ingress and egress routers are NEs Edge model: access routers of source and destination sites are NEs TTL monitoring detected 40% - 90% route changes in different models NSIS-Concerned Route Changes - the subset of route changes that involve change of NSIS Entities (NEs) Old path New path Data flow direction Route Change Detection Methods Routing monitoring (BGP, OSPF) - Local trigger - Extended trigger Packet monitoring (TTL/Interface) - Connection-mode signaling messages - Data packets Datagram-mode probing

As part of the IETF NSIS working group we are standardizing a generic IP signaling protocol that separates the transport of the signaling from the application signaling (e.g., QoS, NAT traversal).