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

2. 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

3. 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

4. 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