SCTP and NAT draft-ietf-behave-sctpnat-00.txt Randall Stewart - - PowerPoint PPT Presentation

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SCTP and NAT draft-ietf-behave-sctpnat-00.txt Randall Stewart - - PowerPoint PPT Presentation

Oct 23, 2023 10 likes •100 views

SCTP and NAT draft-ietf-behave-sctpnat-00.txt Randall Stewart (rrs@lakerest.net) Michael Txen (tuexen@fh-muenster.de) Irene Rngeler (i.ruengeler@fh-muenster.de) Message Format Common Header First Chunk Second Chunk Third Chunk Last Chunk Common

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SLIDE 1

SCTP and NAT

draft-ietf-behave-sctpnat-00.txt

Randall Stewart (rrs@lakerest.net) Michael Tüxen (tuexen@fh-muenster.de) Irene Rüngeler (i.ruengeler@fh-muenster.de)

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SLIDE 2

Message Format

Common Header First Chunk Second Chunk Third Chunk Last Chunk

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SLIDE 3

Common Header Format

Source Port Destination Port Verification Tag Checksum

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SLIDE 4

A NAT with NAPT capabilities for SCTP

  • Does not use the port numbers to identify the

SCTP association, but the verification tag.

  • The IP address is modified based on the port

numbers and the verification tag.

  • No recalculation of the checksum is necessary.
  • No change of the port number is required.
  • If an ephemeral port number is used one has a

32+14 = 46 bit random number for identifying the association.

  • Every packet contains only one verification tag

(except for the INIT-ACK).

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SLIDE 5

Changes

  • Address single- and multi-homed scenarios.
  • Address client-server and peer to peer scenarios.
  • Adopted terminology.
  • Clarified figures.
  • We added a lot of examples, showing the message

flow and the state changes in the NAT box.

  • Addressed all comments we got.
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SLIDE 6

Terminology

Internal Network | External Network

| Private | Public External +---------+ Address | Address /--\/--\ Address +---------+ | SCTP | +-----+ / \ | SCTP | |end point|==========| NAT |======= | Internet | ========== |end point| | A | +-----+ \ / | B | +---------+ Internal | \--/\--/ External +---------+ Internal Port | Port External VTag | VTag

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SLIDE 7

Implementations

  • The Swinburne University of Technology has

implemented the middlebox behavior on FreeBSD.

  • Münster University of Applied Sciences has

implemented implemented the middlebox and endpoint behavior in a simulation tool.

  • Münster University of Applied Sciences is working
  • n the middlebox behavior on Linux.
  • Endpoint behavior on FreeBSD is also coming…
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SLIDE 8

To Do

  • Incorporate some of the comments received

form the Swinburne University of Technology.

  • Add some more examples.
  • IPv6?
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SLIDE 9

Questions