Static Context Header Compression SCHC drafttoutain6 lpwaipv 6

Static Context Header Compression (SCHC) draft-toutain-6 lpwa-ipv 6 -static-context-hc-01 draft-toutain-lpwan-yang-static-context-hc-00 Laurent Toutain - Ana Minaburo Laurent. Toutain@telecom-bretagne. eu ana@ackl. io IETF 96 - Berlin LPWAN@IETF 96 1

Advantages of Ro. HC and 6 Lo(WPAN) • Ro. HC: flexible, field description • 6 Lo(WPAN): IPv 6 address compression Context: • Efficient compression • Adapted to LP-WAN architecture: – Star topology – Nodes with predictable traffic LPWAN@IETF 96 2

Static Context Header Compression Uncompressed header Card 1 12 Header description Uncompressed header rule Card 1 12 Header description context Rule id or shim id Card 12 (+data) LPWAN@IETF 96 3

Context /----------+-------------------- | Function | Compression | Decompression | | | +----------+--------------------+ |elided |not sent |use value stored in ctxt | |send-value |send |build field from value | |compute-IPv 6 -length |elided |compute IPv 6 length | |compute-UDP-length |elided |compute UDP length | |compute-UDP-checksum|elided |compute UDP checksum | |ESiid-DID |elided |build IID from L 2 ES addr | |LCiid-DID |elided |build IID from L 2 LA addr | ----------+--------------------/ LPWAN@IETF 96 5

Static Context Header Compression End System ctxt L C LPWAN@IETF 96 LPWAN Radio LPWAN Gateway LPWAN Application L C ctxt 6

Static Context Header Compression End System LPWAN Radio LPWAN Gateway LPWAN Application L C ctxt Shim id L C ctxt Be used for legacy applications Optimization: Out of scope for IETF -need to reconstruct IPv 6 and ULP forwarding and authentication LPWAN@IETF 96 7

Static Context Header Compression • Static: Values do not evolve during transmission: – IPv 6/UDP have only static values – Co. AP can also be compressed: • More complex: asymmetric compression LPWAN@IETF 96 8

Yang model for SCHC +--rw generic-rules | +--rw context-name? | +--rw context-rules* [rule-id] | +--rw rule-name? | +--rw rule-id | +--rw rule-fields* [field-pos] | +--rw field-name? | +--rw field-pos | +--rw field-value? | +--rw field-compression-match | | +--rw operator? | | +--rw (operator-lsb)? | | +--: (lsb-length) | | +--rw lsb-length? | +--rw field-decompression-match | | +--rw operator? | | +--rw (operator-lsb)? | | +--: (lsb-length) | | +--rw lsb-length? | +--rw action-function? LPWAN@IETF 96 string int 8 LPWA-types enumeration LPWA-types LPWA-action-functions 9

With Co. MI/Co. OL End System ctxt L C LPWAN Radio LPWAN Gateway ctxt L C ESPrefix ≈ SLAAC i. PATCH /c Content-Format(application/cool-value-pairs+cbor) [ [field-SID, rule-id, field-pos], value ] LPWAN@IETF 96 10