submission doc.: ieee 11-12/0273r8 may 2012 hiroki nakano, trans new technology, inc.slide 1 sfd...

Submission

doc.: IEEE 11-12/0273r8May 2012

Hiroki Nakano, Trans New Technology, Inc.Slide 1

SFD Text for Upper LayersDate: 2012-05-14

Authors:Name Affiliations Address Phone email

Hiroki Nakano Trans New Technology, Inc.

Sumitomo Seimei Kyoto Bldg. 8F,62 Tukiboko-cho, Shimogyo,Kyoto 600-8492 JAPAN

+81-75-213-1200

[email protected]

Hitoshi Morioka

Allied Telesis R&D Center

2-14-38 Tenjin, Chuo-ku Fukuoka 810-0001 JAPAN

+81-92-771-7630

[email protected]

Submission

doc.: IEEE 11-12/0273r8

Hiroki Nakano, Trans New Technology, Inc.

Abstract

DCN: IEEE11-12/0273r8

Title: SFD Text for Higher Layers

Authors and Companies:

Hiroki Nakano (Trans New Technology, Inc.)

Hitoshi Morioka (Allied Telesis R&D Center)

Scope: Upper layer

Motivation: page 3 (abstract)

Background information: page 4-22

Motion: page 23-27 including five motions

Slide 2

May 2012

Submission

doc.: IEEE 11-12/0273r8May 2012


Slide 3

Motivation

• An IP(v4) address are normally assigned by DHCP(v4) and the specification of DHCP is stable. DHCP includes definition of state transition and have lots of extensions derived from lots of past discussions. Non-AP STA should be still a DHCP client.

• The discussions of IPv6 address assignment are still going on actively in IETF and its specification is being changed. We should provide a framework for them.

• In addition, TGai should not deny the other protocols because we are the link layer.

Submission

doc.: IEEE 11-12/0273r8


Background Information

Common abbreviation:

DHCP: Dynamic Host Configuration Protocol, which is defined by RFC2131 and the other supplemental RFCs.

Slide 4

May 2012

Submission

doc.: IEEE 11-12/0273r8May 2012


The past Straw poll 1

Do you support to add the following text to the clause 4 of SFD:

“The TGai amendment defines a method of IP(v4) address assignment which works as a transport of DHCP.”

Yes: 5 No: 3 Don’t care: 17(Mar 15 AM1)

Submission

doc.: IEEE 11-12/0273r8May 2012


The past Straw poll 2

Do you support to add the following text to the clause 4 of SFD:

“The TGai amendment defines a generalized method for upper layer transport encapsulation during FILS to enable higher layer services.”

Yes: 7 No: 1 Don’t care: 22(Mar 15 AM1)

Submission

doc.: IEEE 11-12/0273r8May 2012


Proposed Amendment 1

Clause to amend: Section 3

Add to the last of Section 3:

3.x Encapsulation Framework for HLCF

The TGai amendment defines a generalized method for upper layer transport encapsulation during FILS to enable higher layer services.

Submission

doc.: IEEE 11-12/0273r8May 2012


Motivation of Proposed Amendment 1

• This sentence intends TGai to support IPv4, IPv6 and other upper layer protocols.

• Transparency as a link layer is important in order to support various upper layer protocols.

Submission

doc.: IEEE 11-12/0273r8May 2012




Add to the last:

5.x IPv4 support

The TGai amendment defines a method of IP(v4) address assignment which works as a transport of DHCP.

Submission

doc.: IEEE 11-12/0273r8May 2012


Proposed Amendment 2 (Supplement)


Add to appropriate line:

DHCP: Dynamic Host Configuration Protocol, which is defined by RFC2131 and the other supplemental RFCs.

Submission

doc.: IEEE 11-12/0273r8May 2012



• This sentence intends TGai to provide standard implementation technique of IP(v4) address assignment by DHCP. Our PAR says TGai is required to support “IP address assignment” as an example.

• The specification of DHCP is quite stable and widely deployed, therefore it is eligible to be referred by TGai.

• The following slides show that a function as a transport is sufficient to achieve the goal of TGai.

Submission

doc.: IEEE 11-12/0273r8


Prerequisite

• DHCP with RCO have ability to complete an IP address assignment with a round-trip exchange of frames.• DHCP: Dynamic Host Configuration Protocol (RFC2131)

• RCO: Rapid Commit Option define (RFC4039)

Slide 12

May 2012

Submission

doc.: IEEE 11-12/0273r8


Sequence Example by DHCP with RCO

May 2012

Slide 13

Non-AP STA AP DHCP server

DH

CP

Cli

ent S

oftw

are

Processing for security

DHCP Discover w/ RCO

DHCP Ack

AS

At this point, Non-AP STA has been authenticated.

AP keeps a DHCP packet. Maximum time is assumed to be less than 100 msec.

less

than

100

ms

(See

TG

ai F

unct

iona

l Req

uire

men

ts)

Submission

doc.: IEEE 11-12/0273r8


Comments & Answers

• Frames get bigger. It’s the problem.• TGai intends to reduce exchanges of packets, not reduce

information itself. Therefore, it is natural that less exchanges leads to bigger packets. A round trip of 1000-byte-long frames is obviously preferable to 10 round trips of 100-byte-length packets.

• TGai can provide special “compression” encodings for specific upper layer protocols, such as DHCP. For instance, most of DHCP packets have about 200-byte-long consecutive zeros and a generic data compression technique or a special encoding for DHCP can compress DHCP packets without changing information.

Slide 14

May 2012

Submission

doc.: IEEE 11-12/0273r8


Comments & Answers

• What packets should be forwarded or not? Does it affect security?• Basically, piggybacked frames of upper layers should be

forwarded after authentication is finished. Essentially, non-AP STA can throw any kind of packets for upper layers after authentication.

• If you want a further optimization such as a premature start of IP address assignment processing before completion of authentication, you must consider security mechanism such as packet filtering. However, this is out of our scope, although TGai does not prevent such techniques.

Slide 15

May 2012

Submission

doc.: IEEE 11-12/0273r8


Comments & Answers

• How long does an AP wait for a response from DHCP server?• The TGai Functional Requirements document requests to provide

a secure link set-up in less than 100 ms.

• Therefore, Maximum time for an AP to wait is 100ms.

• DHCP packets transfer between an AP and a non-AP STA in a normal manner after 802.11ai link setup. If a response from DHCP server reaches an AP after the AP sends a response to non-AP STA, DHCP packets can be sent in the same manner as Data frames.

Slide 16

May 2012

Submission

doc.: IEEE 11-12/0273r8


Comments & Answers

• Do APs require to keep HLCF (DHCP) packets during processing for security? Does this enable attackers to consume memory of APs?• TGai assumes that each authentication for each non-AP STA is

finished within 100ms. See Section 2.2.1 “Link Set-Up Time” of TGai Functional Requirements (IEEE 11-11/0745r5)

• Our media 802.11 can transfer 5000 packets per second at most.

• The size of a HLCF packet is 1500 byte at most.• MTU of 802.11 is about 2300 byte.

• Therefore, amount of packets for AP to keep is 750KB at most in case that all packets flying are employed for attacks.

Slide 17

May 2012

Submission

doc.: IEEE 11-12/0273r8


Comments & Answers

• The specific name of a protocol, e.g. “DHCP”, is not suitable for SFD!• DHCP is obviously the most deployed protocol in protocols for IP

address assignment function on the 802 network.

Slide 18

May 2012

Submission

doc.: IEEE 11-12/0273r8May 2012




Add to the last:

5.x IPv6 support

The TGai amendment does not define any detail of IPv6 address assignment and does encourage IPv6 to use a generalized method for upper layer transport encapsulation defined by the TGai amendment.

Submission

doc.: IEEE 11-12/0273r8May 2012



• The discussions of IPv6 address assignment are still going on actively in IETF and its specification is being changed. We should provide a framework for them.

Submission

doc.: IEEE 11-12/0273r8May 2012




Add to the last of Section 5:

5.x Forwarding of HLCF information

The TGai amendment defines HLCF as an AP forwards information carried from an non-AP STA by HLCF to the others than the non-AP STA only either after successful authentication or with assurances of the same security level as the existing 802.11 security framework.

Submission

doc.: IEEE 11-12/0273r8May 2012



• Any request prohibits to be processed before it is validated.

Submission

doc.: IEEE 11-12/0273r8May 2012


Motion 1

Move to add the following text to the Section 3 of SFD:

“3.x Encapsulation Framework for HLCF

The TGai amendment defines a generalized method for upper layer transport encapsulation during FILS to enable higher layer services.”

Moved:

Seconded:

Yes: No: Abstain:

Submission

doc.: IEEE 11-12/0273r8May 2012


Motion 2


“5.x IPv4 support

The TGai amendment defines a method of IP(v4) address assignment which works as a transport of DHCP.”

Moved:

Seconded:

Yes: No: Abstain:

Submission

doc.: IEEE 11-12/0273r8May 2012


Motion 2a


“DHCP: Dynamic Host Configuration Protocol, which is defined by RFC2131 and the other supplemental RFCs.”

Moved:

Seconded:

Yes: No: Abstain:

Submission

doc.: IEEE 11-12/0273r8May 2012


Motion 3


“5.x IPv6 support

The TGai amendment does not define any detail of IPv6 address assignment and does encourage IPv6 to use a generalized method for upper layer transport encapsulation defined by the TGai amendment.”

Moved:

Seconded:

Yes: No: Abstain:

Submission

doc.: IEEE 11-12/0273r8May 2012


Motion 4


“5.x Forwarding of HLCF information

The TGai amendment defines HLCF as an AP forwards higher layer information between an non-AP STA and the others than the non-AP STA only either after successful authentication or with assurances of the same security level as the existing 802.11 security framework.”

Moved:

Seconded:

Yes: No: Abstain:

Submission

doc.: IEEE 11-12/0273r8May 2012


Slide 28

Backup

Submission

doc.: IEEE 11-12/0273r8


New

sof

twar

e fo

r ne

w p

roto

col

A possible counterproposal

May 2012

Slide 29

Non-AP STA AP DHCP server

Processing for security

TGai new protocol

DHCP Discover w/ RCO

TGai new protocol

DHCP Ack

Translation?

Translation?

Submission

doc.: IEEE 11-12/0273r8


Comparison

DHCP with RCO New protocol w/ DHCP-like frame format

New protocol

Frame exchange 1 round trip 1 round trip 1 round trip

Non-AP STA is DHCP client TGai client TGai client

AP is a forwarder often a DHCP client often a DHCP client

TGai is a transport a protocol for IP address assignment

a protocol for IP address assignment

What information is distributed? DHCP defines DHCP defines (including

future extensions?) TGai defines

Behavior of non-AP STA DHCP defines TGai defines TGai defines

Behavior of AP a forwarder TGai defines TGai defines

AP has no state some state(?) some state(?)

When an address assignment expires

DHCP uses normal transport to extend

TGai defines extending procedure

TGai defines extending procedure

Slide 30

May 2012

submission doc.: ieee 11-12/0273r8 may 2012 hiroki nakano, trans new technology, inc.slide 1 sfd...

Documents

sfd text

transport of dhcp

hlcfthe tgai amendment

specification of dhcp

following text

higher layer services

link layer

dhcp client