SMI to XSD Translations

IETF70

David Harrington

Agenda

• The Need

• The Approaches

• Comparisons

IETF69 XSDMI BOF

• Proposal – a standard XSD translation for SMIv2 types, textual conventions, and macros for MIB definitions

• Goal – any XML-based protocol or implementation can leverage existing SMIv2 types, textual conventions, MIB structures, and existing code.

• BOF Results: 13-0 in favor

Post-BOF

• Decision to bring it to OPSAWG rather than start a whole new WG for this fairly simple work

• YANG proposes an SMI-YANG-XSD translation path using tools.

• Proponents of YANG concerned that a standard SMI-XSD translation would constrain YANG work.

• Concern over competing standards slowed progress.

Moving Forward

• Compare the current YANG tools with the XSDMI definitions, and other SMI-XSD translations of data types, etc.

• Determine how far apart we are

• Determine if we can eliminate differences

• Determine why some differences might be needed.

The Approaches - XSDMI

• Draft-romascanu-netconf-datatypes-00 hand-crafted translations of SMI types and textual conventions

• Goal- to quickly provide types for implementers developing their own proprietary XML data models for Netconf

• Rough consensus on the need.• Work stopped when Romascanu became

AD.

The Approaches - XSDMI

• Work restarted by Li Yan when original authors no longer available.

• SMI is a separate standard from SNMP and from MIB modules, per RFC1052.

• Draft-romascanu-netconf-datatypes-01,02 positioned as protocol-independent translation to meet standard and proprietary needs for Netconf, MIB2RDML, and other uses.

The Approaches - XSDMI

• Libsmi is a popular open-source toolkit for validating MIB modules. Smidump (from libsmi toolkit) can translate a MIB module into XSD.

• Draft-romascanu-netconf-datatypes-01,02 based on documenting the open source code translation algorithms of smidump.

• “Running code” for SMI-XSD translations.

The Approaches – MIB2RDML

• MIB2RDML wants to make existing MIB available for reuse in Web Services environments by providing translations of SMI types, TCs, and structures.

• Leader of MIB2RDML recognized this could be done in two steps – SMI-XSD and then XSD-RDML (and other).

• Bob Natale joined XSDMI team after BOF.

The Approaches – XSDMI/MIB2RDML

• Draft-li-netconf-datatypes-03 unfocused due to competing use cases; confusion over relation to netconf; never published.

• We improved focus on SMIv2 fidelity and netconf-independence.

• New cleaner draft with a new name – draft-li-natale-smi-datatypes-in-xsd-00

• Would like to make this simply an OPSAWG draft – not XSDMI, not YANG, not MIB2RDML

The Approaches - YANG

• YANG is focused on Netconf. Period.

• YANG based on “running code” from multiple sources (Juniper, Tail-f, Ericsson, Bierman, libsmi)

• YANG can import SMI MIB modules (including types, TCs, structures)

• Tools include smidump and pyang.

• Tools provide YANG-to-XSD translations.

The Approaches - YANG

• YANG specs are incomplete. As a result, the tools are still in development

• Current XSD output of tools doesn’t match

Proposal

• I have XSD from – Romascanu-netconf-datatypes-03– Pyang output– Smidump output

• Let’s look these over and decide how different they are.

• Let’s decide whether it makes sense to try to reach consensus on the XSD format

Proposal

• Can these XSD formats be “harmonized”?

• We may need to accept that SMI to XSD translations might differ to meet requirements of different protocols

• If translations are protocol-independent, this is an OPS area task.

• Should this harmonizing be done in OPSAWG?

Thank You

• Questions?