NTLP strawman draft-schulzrinne-gimps Henning Schulzrinne Columbia University 30 July 2019 IETF57 - NSIS

Philosophy/approach "Tool kit" approach: RSVP-like in philosophy: allow different NSLPs to choose trade-offs as needed: from unreliable one-shot to reliable large-message delivery allow NEs to choose time vs. space trade-off RSVP-like in philosophy: follow data path (but logically separable) soft state state time-out, with explicit state removal Transport philosophy: do easy parts within simple transport: small messages (< 500 bytes)  no fragmentation first messages in session (unknown next hop) reliable hop-by-hop delivery leave hard parts to real transport protocols: invoked only when needed offer fast recovery (< n*RTT), flow control, congestion control, fragmentation, … 30 July 2019 IETF57 - NSIS

Other design choices TLV structure like RSVP Refresh reduction like 2961 (needs details) No explicit support for multicast but addable – strict hop-by-hop behavior should make this easy 30 July 2019 IETF57 - NSIS

What needs work Name  State maintenance for transport state: remove when last session state removed remove after idle timer (trade space for time) remove LRU when out of space State estimate (~ sessions + next hops) Describe NSLP-specific next-hop selection Packet format Multihoming NAT behavior Mobility behavior primarily dead-branch removal Security mechanisms can negotiate TLS and IPsec how much is really needed 30 July 2019 IETF57 - NSIS